Dynamic update of an application in compilation and deployment with hot-swapping

ABSTRACT

In some examples, method includes, in response to receiving an initial user input that causes a builder computing system to compile a set of source code for an application into a set of compiled targets, deploying the set of compiled targets to initiate execution of the application, wherein a subset of the set of source code is compiled into an initial subset of the set of compiled targets; after modification to at least the subset of the set of source code, receiving a subsequent user input that causes the builder computing system to compile at least the subset of the set of source code into an updated subset of the set of compiled targets; and in response to determining that the updated subset differs from the initial subset, deploying the updated subset to update the application based on the updated subset without terminating execution of the application.

This application claims the benefit of U.S. Provisional Application No.62/258,335, filed Nov. 20, 2015, the entire content of which is herebyincorporated by reference.

BACKGROUND

Software developers may write computer programs in human-readable sourcecode that conforms to a particular syntax. By writing computer programsin human-readable source code, software developers may design andimplement computer programs more efficiently than writing programsdirectly in machine readable code. To execute computer-programs that areinitially written in human-readable source code, a compiler maytransform the human-readable source code into machine-readable code,which may be interpreted by a virtual machine or executed directly by aparticular computer processing unit (CPU) architecture. Each time asoftware developer changes human-readable source code in a computerprogram, to test or observe a change in functionality, the softwaredeveloper must initiate a build process to re-compile the source codeinto machine-readable code. The build process may include compiling,packaging, deploying, and executing machine-readable code to observe ortest the changed functionality. As the lines of code increase in acomputer program, the build process may require greater amounts of timeto complete. As such, a software developer that frequently executes thebuild process may experience increasing losses in productivity as thesize of an application grows due to downtime that the developer incurswhile waiting for the build process to complete.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a conceptual diagram illustrating a builder computing systemthat may detect changes to a set of targets generated in a build processfor an application and deploy a subset of the targets that have changedto the application executing at a test environment system, in accordancewith techniques of the disclosure.

FIG. 2 is a flowchart illustrating software compilation and buildprocess that may be performed by a builder computing system of FIG. 1,in accordance with one or more aspects of the present disclosure.

FIG. 3 is a block diagram illustrating a builder computing device as anexample computing device configured to perform an example softwarecompilation and build process, in accordance with one or more aspects ofthe present disclosure.

FIG. 4 is a block diagram illustrating a test environment system as anexample computing device configured to execute an application, inaccordance with one or more aspects of the present disclosure.

FIG. 5 is a flow diagram illustrating example operations of a buildercomputing system configured to perform hot-swapping techniques, inaccordance with techniques of this disclosure.

FIG. 6 is a flow diagram illustrating example operations of a testenvironment system configured to perform hot-swapping techniques, inaccordance with techniques of this disclosure.

FIG. 7 is a flow diagram illustrating example operations of a buildercomputing system configured to perform cold-swapping techniques, inaccordance with techniques of this disclosure.

FIG. 8 is a flow diagram illustrating example operations of a testenvironment system configured to perform cold-swapping techniques, inaccordance with techniques of this disclosure.

FIG. 9 is a flow diagram illustrating example operations of a buildercomputing system configured to perform warm-swapping techniques, inaccordance with techniques of this disclosure.

FIG. 10 is a flow diagram illustrating example operations of a testenvironment system configured to perform warm-swapping techniques, inaccordance with techniques of this disclosure.

DETAILED DESCRIPTION

Techniques of the disclosure are generally directed to improvingproductivity of software developers by reducing the amount time neededto build and deploy incremental changes within an application. Forinstance, a builder computing system may initially generate anapplication package the represents an application. The applicationpackage may include machine-readable code (e.g., compiled targets) thatis compiled from source code and may also include resources, such asimages or any other uncompiled content. When a software developerinitially builds the application package, the builder computing systemcompiles the source code, assembles the resources, packages both theresources and machine readable code into the application package, andsends the application package to a test environment system forexecution. Rather than repeating this process each time the softwaredeveloper makes a change to a subset of the source code and/orresources, techniques of the disclosure may, for incremental changes,send the subset of changed compiled and uncompiled targets to the testenvironment system. In this way, the more extensive and time-consumingprocess of building the entire application package each time may beavoided.

The techniques may also enable the application to execute updatedmachine readable code without terminating execution of application. Forinstance, when initially building the application package, the buildercomputing system may inject bytecode into an original compiled targetthat causes the original compiled target to check whether an updatedversion of the compiled target exists, and if so, execute program logicfrom the updated compiled target. When the original compiled target isloaded into memory of the test environment system and is executed, theprogram logic of the original compiled target is executed. However, ifthe software developer makes a change to source code for the compiledtarget, the builder computing system may generate the updated compiledtarget, which includes one or more indicators that the updated compiledtarget is a modified version of the original compiled target. Thebuilder computing system may deploy the updated compiled target to thetest environment system, and the test environment system may store areference within the original compiled target to the updated compiledtarget. If program logic of the original compiled target is laterexecuted, the original compiled target may determine that an updatedversion of the original compiled target exists, and invoke program logicof the updated compiled target. Because the application may be updatedbased on the changes without terminating execution of application, theapplication may retain its state during execution while exhibitingupdates in its functionality from the updated compiled target.Additional techniques of this disclosure may update uncompiled targetssuch as resources and may also revert back to restarting the applicationif changes cannot be applied to an application without restarting.

FIG. 1 is a conceptual diagram illustrating a builder computing system102 that may detect changes to a set of targets generated in a buildprocess for an application and deploy a subset of the targets that havechanged to the application executing at a user computing system 124, inaccordance with techniques of the disclosure. In the example of FIG. 1,builder computing system 102 may be a desktop computer. However, inother examples, builder computing system 102 may be a tablet computer, asmartphone, a laptop computer, workstation, server, or another type ofcomputing device. Builder computing system 102 may be a computing deviceused by a software developer to write computer programs comprised ofsource code, and compile the source code in an executable computerprogram. In some examples, builder computing system 102 may be a serverthat is accessed by a computing device of a software developer via anetwork to compile source code into a computer program. Although notshown in FIG. 1, builder computing system 102 may include applicationsand/or modules in addition to builder module 108. For instance,computing device 102 may include an operating system, web browser,command line terminal, or any other applications and/or modules that areexecutable by a computing device, to name only a few examples.

Builder computing system 102 may include an integrated developmentenvironment (IDE) 104. IDE 104 may be implemented as hardware, software,or a combination of hardware and software. In some examples, IDE 104 isa software application that includes a set of tools to design, debug,profile, and deploy applications, to name only a few examples. IDE 104,as shown in FIG. 1, includes an editor 106 and builder module 108. Insome examples, one or more modules shown as included within buildermodule 108 may exist separately from builder module 108. In someexamples, builder module 108 may include other components not shown inbuilder module 108, such as a profiling tool to measure applicationperformance or a modeling tool to visually represent and designcomponents to name only a few examples.

In some examples, editor 106 is a text editor. Text editor 106 mayprovide functionality for editing source code and other text. Forinstance text editor 106 may include syntax highlighting,code-completion, refactoring, and/or code-generation functionality toname only a few examples. Using text editor 106, a software developermay compose and edit source code 118 for an application 130. Applicationsource code 118 may define controller logic, the model, andfunctionality of the presentation logic for application 130. In additionto source code 118, a software developer may also generate, assemble, ororganize, application resources 120 that are included in application 130or are used by builder module 108 to generate an application.Application resources 120 may include but are not limited to buildscripts, source code or markup language that defines an appearancegraphical user interface, and data files (e.g., text files, images, etc.included in the application).

Builder module 108 may receive one or more application resources 120 andsource code 118, which builder module 108 may compile and/or assembleinto one or more applications, such as application 130. Builder module108 may include one or more sub-components to process and compileapplication resources 120 and application source code 118. For instance,as shown in FIG. 1, builder module 108 may include a preprocessor 104and a compiler 114. Preprocessor 116 may perform preliminary analysisand/or transformations on source code 118 and/or resources 120 prior tocompilation at compiler 114. For instance, pre-processor 116 may parseand/or transform layout files that define a particular visual layout fora graphical user interface or perform preliminary checks fordependencies or syntax errors. In some examples, pre-processor 116 mayorchestrate or coordinate the build process based on one or more buildscripts.

Builder module 108 may also include a compiler 114. Compiler 114 maycompile human-readable source code into machine-executable code. Forinstance, compiler 114 may perform lexical analysis of thehuman-readable source code. Lexical analysis may include dividing syntaxelements of the source code into tokens. Each token may correspond to asymbol in a programming language, such as a keyboard, variable, ornumber. Compiler 114 may also perform syntax analysis on the tokens. Forinstance compiler 114 may generate a tree data structure, called asyntax or parse tree, which organizes the tokens based on therelationships between syntax elements that correspond to the tokens.Each node of the syntax tree may represent a token. As such, the syntaxtree may represent the structure or organization of the computerprogram. Compiler 114 may also perform type checking on the syntax treeto determine if one or more programming language requirements areviolated.

Compiler 114 may convert the human-readable source code in a syntax treeinto machine-independent intermediate code, while in other examples,compiler 114 may convert the human-readable source code into assemblylanguage for a specific machine architecture. For purposes of thisdisclosure, machine-executable code may refer to machine-independentintermediate code or assembly language for a specific computerarchitecture. The machine-independent intermediate code may be executedby a runtime environment or virtual machine that has been compiled for aspecific computer architecture, while assembly language for a specificmachine architecture is executed directly by a processor having aparticular computer architecture.

As shown in FIG. 1, builder module 108 includes debugger 117. Debugger117 provides debugging functionality, such as single-stepping andbreaking through execution of application 130. In some examples,debugger 117 may provide for inspection of values assigned to variablesin application 130 during execution, such that a software developer canview the values.

Compiler 114 may generate a target set 112 that includes one or moretargets. A target may be compiled or uncompiled. In some examples, atarget is a single file. For instance, a target may be a file thatincludes a set of machine-executable code (e.g., “compiled target”)compiled from human-readable source code. A compiled target may bereferred to as an object definition in object-oriented programming. Insome examples, a target may have a particular name and may be a logicalgrouping of machine-executable code. For instance, in the Javaprogramming language, a compiled target may be a compiled class file(e.g., object definition) with the same name as a source file thatdefines the logic of the compiled class file.

In some examples, a target may be an uncompiled target. An example of anuncompiled target may be a resource that is accessed, integrated, orotherwise used with an application. For instance an uncompiled targetmay be an image, layout definition, color definition, or the like. Whenbuilding application 130, builder module 108 may assemble a target set112 that includes compiled and uncompiled targets that collectivelyrepresent application 130. For instance, application 130 may be acollection of compiled targets and uncompiled targets that are bundledinto a single file called an application package.

As shown in FIG. 1, during the software development process, a softwaredeveloper may cause builder module 108 to compile source code 118 andassemble resources 120 into target set 112, which may be bundled bybuilder module 108 into an application package that representsapplication 130. Application 130 may be executed in test environmentsystem 124 to observe or test functionality implemented in application130. In FIG. 1, test environment system 124 is implemented as a separatecomputing device that is coupled to builder computing system 102 by acommunication link 119. Examples of test environment system 124 mayinclude, but are not limited to a tablet computer, a personal digitalassistant (PDA), a laptop computer, server, desktop computer, a portablegaming device, a portable media player, an e-book reader, a smartwatch,television platform, or another type of computing device. Communicationlink 119 may be a wired or wireless link that operably couples buildercomputing system 102 to user computing system 124. Builder module 108may deploy application 130 to test environment system 124 by sending acollection of compiled targets and uncompiled targets that representapplication 130 to test environment system 124 via communication link119. For instance, builder module 108 may deploy application 130 bysending an application package that represents application 130 to testenvironment 124.

As shown in FIG. 1, test environment 124 may include apresence-sensitive display 126. Presence-sensitive display 126 of testenvironment 124 may function as an input device and as an output devicefor test environment 124. In some examples, presence-sensitive display126 may include an integrated presence-sensitive input device and adisplay device. For instance, presence-sensitive display 126 mayfunction as a presence-sensitive input device using a presence-sensitivescreen, such as a resistive touchscreen, a surface acoustic wavetouchscreen, a capacitive touchscreen, a projective capacitancetouchscreen, a pressure-sensitive screen, an acoustic pulse recognitiontouchscreen, or another presence-sensitive screen technology.Presence-sensitive display 126 may function as an output device, such asa display device, using any one or more of a liquid crystal display(LCD), dot matrix display, light emitting diode (LED) display, organiclight-emitting diode (OLED) display, e-ink, or similar monochrome orcolor display capable of outputting visible information to the user oftest environment 124.

Presence-sensitive display 126 may receive indications of the user inputby detecting one or more tap and/or non-tap gestures, continuousgestures, or other any touch gestures (e.g., multi-touch gestures)received by test environment 124 (e.g., the user touching or pointing toone or more locations of presence-sensitive display 126 with a finger ora stylus pen). Based on indications of user input, a display device ofpresence-sensitive display 126 may present output to a user. Forinstance, a display device of presence-sensitive display 126 may presentvarious user interfaces of applications executing at test environment124. A user of test environment 124 may provide user input at apresence-sensitive input device of presence-sensitive display 126 tointeract with one or more of these applications.

Test environment 124 may also include user interface (UI) module 128. UImodule 128 of test environment 124 may receive from presence-sensitivedisplay 126, one or more indications of user input detected atpresence-sensitive display 126. Generally, each time presence-sensitivedisplay 126 receives an indication of user input detected at apredefined location of presence-sensitive display 126, UI module 128 mayreceive information about the user input from presence-sensitive display126. UI module 128 may assemble the information received frompresence-sensitive display 126 into a set of events, which may betime-ordered, that are indicative of a gesture, such as a sequence ofone or more touch events. Each touch event in the sequence may includedata or components that represents parameters (e.g., when, where,originating direction) characterizing a presence and/or movement ofinput at the presence-sensitive screen. Each touch event in the sequencemay include a location component corresponding to a location ofpresence-sensitive display 126, a time component related to whenpresence-sensitive display 126 detected user input at the location,and/or an action component related to whether the touch eventcorresponds to a lift up or a push down at the location. Moreover, oneor more of the events may have a concurrent time component, and suchevents are described as touch events merely for purposes of example andmay be indicative of a gesture at any form of presence-sensitive inputdevice.

UI module 128 may determine one or more characteristics of the userinput based on the sequence of touch events and include informationabout these one or more characteristics within each touch event in thesequence of touch events. For example, UI module 128 may determine astart location of the user input, an end location of the user input, adensity of a portion of the user input, a speed of a portion of the userinput, a direction of a portion of the user input, and a curvature of aportion of the user input. One or more touch events in the sequence oftouch events may include (in addition to a time, a location, and anaction component as described above) a characteristic component thatincludes information about one or more characteristics of the user input(e.g., a density, a speed, etc.). UI module 128 may transmit otherwisemake available to application module 114 the sequence of touch eventsincluding the components or parameterized data associated with eachtouch event.

UI module 128 may act as an intermediary between various components oftest environment system 124 to make determinations based on inputdetected by presence-sensitive display 126 and generate output presentedby presence-sensitive display 126. For instance, UI module 128 mayreceive, as an input from application 130, a representation of graphicaluser interface 140 that includes input fields 142A-142C. UI module 128may also receive a sequence of touch events generated from informationabout user input detected by presence-sensitive display 126. UI module128 may determine, based on the location components in the sequencetouch events that one or more location components approximate aselection of one or more locations of graphical user interface 140. UImodule 128 may transmit, as output to application 130, the sequence oftouch events. UI module 128 may also receive, information fromapplication 130, which may be output for display at presence-sensitivedisplay 126. UI module 128 may update graphical user interface 140, forexample, to include data within input fields 142A-142C.

Although test environment system 124 is implemented as a computingdevice separate from builder computing system 102 in FIG. 1, in someexamples, test environment system 124 may be implemented at buildercomputing system 102. For instance, test environment system 124 may bean emulator that emulates a device running particular operating system,such as described in FIG. 3. In such examples, test environment system124 executes at builder computing system 102 as hardware, software, or acombination of hardware and software. In some examples, test environmentsystem 124 may be implemented as a virtual machine at builder computingsystem 102. In some examples, test environment system 124 may be one ormore directories in a file system of builder computing system 102 thatinclude or otherwise store the file or files representing application130.

In the example of FIG. 1, application 130, upon being built by buildermodule 106 is deployed to text environment system 124 for execution. Forinstance, builder module 108 may package target set 112 into a singlefile or set of files that builder module 108 sends to test environmentsystem 124. Application 130 may include functionality to perform any ofa variety of operations within test environment system 124. Forinstance, application 130 may be an email application, text messingapplication, instant messaging application, weather application, videoconferencing application, social networking application, weatherapplication, stock market application, emergency alert application,sports application, office productivity application, or multimediaplayer, to name only a few examples.

Test environment system 124, such as a computing device or emulator, mayexecute application 130. As shown in FIG. 1, application 130 may includebut is not limited to object definitions 132, objects state 134 andresources 136. As described above, object definitions 132 may becompiled targets, such as compiled classes in an object-orientedprogramming language. When test environment system 124 executesapplication 130, test environment system 124 may load one or more ofobject definitions 132 into memory. For instance, instructions and/orsymbols included in object definitions 132 may be loaded intorandom-access memory. As shown in FIG. 1, application 130 may includemultiple object definitions. For example, object definition 144Aillustrates human-readable contents of a compiled target for a classthat is named USER. The USER class may define three variables: id (aninteger), firstName (a string), and lastName (a string). Additionally,object definition 144A includes instructions that specify threefunctions or methods: setFirstName, setLastName, and getFullName. Insome examples, a function may refer to a function, instance method classmethod, lamba, or any other suitable relation.

An application may create multiple object instances based on an objectdefinition. For instance, application 130 may create multiple objectinstances based on object definition 144A during the lifecycle ofapplication 130. When application 130 creates or instantiates an objectinstance 146A based on object definition 132, application 130 may invokesystem runtime 138 by specifying the name of the object definition(e.g., “USER”). System runtime 138 may execute on or more system callsthat reserve space in memory for the contents or “state” of eachvariable for the object instance defined based on object definition144A. As shown in FIG. 1, object state 146A represents human-readablestate of an object instance named Instance_1. Object state 146A includesvalues for the variables specified in object definition 144A. Forinstance, object state 146A includes values for each of variables id,firstName, and lastName. In addition object state 146A may include anOBJ_TYPE value that specifies the type of object definition of theobject instance as well as a unique id of the object instance, such asrandomly-generated hashcode. In some examples, a type of target may be adatatype of the target. In some examples, a type may be specific fileextension of the target.

In operation, if program logic in application 130 executes thesetFirstname method of object definition 144A using a reference orpointer to object instance 146, the instructions of setFirstName inobject definition 132 are executed to write the value of ‘first’ to alocation in memory that corresponds to firstName of object state 146A.In addition to object definitions 132 and objects state 134, application130 may include resources 136 as described above. For instance,resources 136 may include images or any other resources that are used byapplication 130.

Each time that a software developer changes functionality in the sourcecode of application 130, the software developer may provide a user inputto initiate the build process at builder module 108. As the size of anapplications grows, the amount of time needed to build and deploy anapplication for each iteration of testing or observing functionality mayalso grow. Because a software developer often does not modify everysource file or logical component defined in source code when changingfunctionality of an application, re-compiling the source code for alltargets, packaging the entire target set into a file representing theapplication, signing the file, and deploying the application may takelengthy periods of time for each build and deploy iteration. Since asoftware developer may modify an application many times in a singleprogramming session, the amount of time per iteration to build anddeploy the application, when measured cumulatively, may impact thesoftware developer's overall productivity in a programming session.Moreover, as changes in functionality are implemented and deployed fortesting and observation, an application that is previously running inthe test environment needs to be restarted in order to execute theupdated changes in functionality.

Techniques of this disclosure may reduce the amount of time to completea build and deploy iteration when incremental changes to functionalityare made in source code following an initial deployment of anapplication. For instance, builder module 108 may implement techniquesto determine when the build process has incrementally generated a subsetof updated compiled targets. Builder module 108 may send the subset ofcompiled targets to test environment system 124 without sending theentire target set 112 for application 130 to test environment system124. In this way, builder module 108 may avoid unnecessary steps in thebuild process such as re-assembling an entire application package thatincludes the entire target set 112, sending the entire applicationpackage to test environment system 124, and re-launching application130. Builder module 108 may further implement techniques that enableapplication 130 to update object definitions 132 that have changedwithout terminating execution of application 130. In this way,application 130 may retain its state while exhibiting the updates in itsfunctionality. These and other techniques are further described hereinwith reference to FIG. 1.

Builder module 108 may implement techniques that enable application 130to update object definitions 132 that have changed without terminatingexecution of application 130. In this way, application 130 may retainits state during execution while exhibiting updates in its functionalityfrom a new build iteration. To enable application 130 to update objectdefinitions 132 that have changed without terminating execution ofapplication 130, builder module 108 may inject program logic intocompiled targets during or after compilation. The additional programlogic may include bolded lines 2-6 of the following pseudocode:

 1 setFirstName(String first) {  2 Object $changeLocal = $change;  3 if($changeLocal != null) {  4 return$changeLocal.access$dispatch(($changeLocal,  5 “setFirstName(Stringfirst)”,first))  6 }  7 // methodName program logic  8 firstName =first;  9 10 // existing setFirstName program logic 11 ... 12 }

In the above example, the method setFirstName (String first) may be amethod of a class (e.g., USER) defined in a source file. Initially, testenvironment system 124 may not include application 130, and buildercomputing system may not include target set 112. To compile application130 for the first time, a software developer may provide a user inputthat causes builder module 108 to build and deploy application 130 in aninitial build and deploy iteration. For purposes of this disclosure,when builder computing system initially builds target set 112, thetarget set 112 may not exist on test environment system 124. That is, asoftware developer may, during the initial build, cause buildercomputing system 102 to generate target set 112 for the first time. Thesoftware developer may, during the initial build, cause buildercomputing system 102 to package target set 112 in an application packageand deploy the application package to test environment 124. During theinitial build, test environment 124 may not have a previous version ofthe application package stored at test environment 124 or may have aprevious version of the application package with a target set that isless recent than target set 112.

During the initial build, builder module 108 may add program logic inthe form of bytecode to a compiled target, where the program logicperforms the functionality of lines 2-6 of the pseudocode whensetFirstName (String first) is invoked. Builder module 108, forinstance, may add a $changeLocal variable to an object definition thatis compiled from the USER class in the source file. The $changeLocalvariable may be used to store a reference or memory location to another,but more recent version, of an object definition of the same type ofUSER class. The $changeLocal variable may be initialized to null, 0, orsome other initialized value.

During the initial build and deploy iteration, builder module 108 mayinclude additional program logic similar to lines 2-6 to each method ofthe USER class, such as setFirstName, setLastName, and getFullName.Builder module 108 may inject the additional program logic as bytecodeat one or more locations of a compiled target that represents the USERclass. In some examples, builder module 108 may determine the specificlocation relative to particular data within the file of the compiledtarget. The particular data may be data representing a compiled targetname (e.g., a class name), a variable name, or a method name. As anexample, builder module 108 may inject the program logic for lines 2-6at a specific location that is prior to data in the compiled target thatspecifies the compiled target name. For instance, the builder module 108may write the program logic for lines 2-6 in bytes prior to but adjacentto bytes in the compiled target that specify the compiled target name.Conversely, builder module 108 may inject the program logic for lines2-6 at a specific location following data in the compiled target thatspecifies the compiled target name. In some examples, builder module 108may inject the program logic for lines 2-6 at a specific location thatis offset from particular data by an offset value.

Builder module 108 may inject program logic for lines 2-6 on a varietyof levels of granularity with a compiled target. For instance, buildermodule 108 may inject program logic for lines 2-6 on a per-compiledtarget basis as described above. In some examples, builder module 108may inject program logic for lines 2-6 on a per-method and/orper-variable basis. As an example, builder module 108 may inject acorresponding bytecode representing program logic for lines 2-6 for eachmethod in a target. In some examples, when a new source file, class,method, or variable is created by a software developer, builder module108 may inject program logic for lines 2-6 as bytecode into thecorresponding compiled target that includes the definition for thecorresponding class, method, or variable. Although techniques above havebeen described with respect to injecting bytecode into a compiled targetafter or during compilations, in some examples, program logic for lines2-6 may be added by preprocessor 116 as human-readable source code tosource files prior to compilation and then compiled to generatemachine-readable code that represents program logic for lines 2-6.

Each compiled target, following injection of the bytecode with theadditional program logic, is included in target set 112. Builder module112 may then package compiled targets and uncompiled targets (e.g.,resources) of target set 112 into an application package that buildermodule 108 may sign and send to test environment system 124. Uponreceiving the application package which includes target set 112, testenvironment system 124 may execute the application package such that oneor more object definitions 132 from target set 112 are loaded intomemory.

At a later time, the software developer may change functionality in themethod getFullName by altering the source code for getFullName. In someexamples, changing the functionality of source code may include addingsource code, deleting source code, renaming source code, rearrangingsource code, or any other modification to the source code. The softwaredeveloper may provide another user input to IDE 104 that causes buildermodule 108 to re-compile the USER class. Builder module 106 maydetermine that an existing compiled target corresponding to the USERclass is in target set 112. Accordingly, builder module 106 may includeinformation in the updated compiled target that indicates the compiledtarget is changed from the existing compiled target. For instance,builder module 106 may modify the class name, method names, and/orvariable names within the updated compiled target to distinguish theclass name, method names, and/or variable names from the originalcompiled target. As an example, builder module 108 may change the classname included in the updated compiled target to USER$override. That is,builder module 108 may inject bytecode or otherwise modify the updatedcompiled target to add the suffix $override to the existing USER classname. In some examples, builder module 108 may inject bytecode orotherwise modify the updated compiled target to add an additionalargument to each method signature of the USER class. In some examples,the additional argument is a reference to an instance of the compiledtarget that called method. For instance, builder module 108 may rewritegetFullName (Object obj, int id) in the updated compiled target.

In some examples, builder module 108 may rewrite instance methods and/orinstance variables as class methods and/or class variables in anoriginal or updated compiled target. In some examples, builder module108 may change access modifiers (e.g., public, protected, private) froma more restrictive scope to a less restrictive scope. For instance,builder module 108 may change access modifiers of classes, methods,and/or variables from private to protected or protected to public. Insome instances, the updated compiled target is injected with one or moreinstances of bytecode that represent the program logic of source codelines 2-6 above.

After builder module 108 has compiled a new version of the USER classinto the updated compiled target, builder module 108 may determine whichother resources and/or compiled targets have been updated. Becausebuilder module 108 previously deployed the entire application package totest environment system 124, builder module 108 may refrain fromperforming unnecessary activities such as re-packaging, signing,aligning, an entirely new application package, and instead determine atarget subset 122 of only those resources and/or updated compiledtargets that have changed. For instance, change detection module 110 maydetermine whether an updated compiled target that was generated bybuilder module 108 more recently than an existing version of a compiledtarget differs from the existing version. Change detection module 110may select the updated compiled targets and resources that have changedas target subset 122. Builder module 108 may deploy or send targetsubset 122 to test environment system 124. In some examples, buildermodule 108 deploys or sends target subset 122 while refraining fromdeploying other compiled targets and/or resources in target set 122 thatare not included in target subset 122. In this way, only the updatedtarget subset 122 of resources and compiled targets is sent to testenvironment system 124.

Upon receiving target subset 122, system runtime 138 may load theupdated compiled target for the USER class into memory while theprevious version of the compiled target is already loaded in memory forexecution of application 130. System runtime 138, when loading theupdated compiled target into memory, may determine a memory location ofor reference to the newer version of the updated compiled target, andstore this memory location or reference in the $change variable of theprevious or original version of the object definition. For instance,system runtime 138 may use reflection to identify and set the $changevariable of the previous version of the object definition. In this way,if application 130 executes setFirstName (String first), the previousversion of the compiled target initially executes its setFirstName(String first) method and determines that ($changeLocal !=null) is truebecause the $changeLocal variable is set to the memory location orreference to the updated version of the compiled target based on the$change variable. As a result, the previous version of the compiledtarget executes $changeLocal.access$dispatch ( ). The access$dispatch ()method includes dispatcher program logic that accepts the arguments($changeLocal, “setFirstName (String first)”, first). The dispatcherprogram logic accesses the updated compiled target based on thereference included in $changeLocal. Upon accessing the updated compiledtarget, the dispatcher executes the method named “setFirstName (Stringfirst)”, using the argument first. Because the dispatcher program logiccan access the updated compiled target using the $changeLocal variablewhile application 130 is executing, changes in functionality to theupdated compiled target may be tested and observed without terminatingexecution of application module 130. Since the execution of applicationmodule 130 has not been terminated, the objects state 134 for existingobject instances may remain accessible in memory. As such, changes tothe updated compiled target can be tested and observed using theexisting objects state.

If the software developer changes the source code again or severaltimes, the process above for sending an updated target set may berepeated. For instance, builder module 108 may send a subsequent updatedcompiled target with injected bytecode to test environment system 124.Test environment system 124 may set the $change variable for thecorresponding, previous updated compiled target to point to or referencethe subsequent updated compiled target that is loaded into memory. Thisprocess may be repeated each time incremental changes are built bybuilder module 108. The original compiled target that was previouslyloaded in memory of the test environment system, in some examples, maybe dereferenced, removed from memory, and/or garbage collected. Thetechniques, as described above, may be referred to in some examples ofthis disclosure as “hot-swapping.” Further techniques for “coldswapping” and “warm swapping” are also described in this disclosure.

FIG. 2 is a flowchart illustrating software compilation and buildprocess that may be performed by a builder computing system 102 of FIG.1, in accordance with one or more aspects of the present disclosure.Process 200 is described in the context of builder module 108 of buildercomputing system 102 of FIG. 1.

Process 200 involves the manipulation and generation of intermediatefiles 220-244 through performance of one or more operations 262-276 forproducing processor executable application program code. That is,intermediate files 220-244 represent the information (e.g., data) thatbuilder module 108 of builder computing system 102 may generate atvarious stages of process 200 as builder module 108 performs one or moreof operations 262-276 to generate code that is executable at a computingdevice, such as test environment 124 of FIG. 1. Process 200 is just oneexample software compilation and build process that builder module 108may perform. In some examples, builder module 108 may generateadditional or fewer intermediate files and/or perform additional orfewer operations than the intermediate files and operations shown inprocess 200. In some examples, builder module 108 may perform theoperations of process 200 in a different order than that shown in FIG. 2and described below.

Builder module 108 may perform resource assembly 262 on one or moreapplication resources 220 to produce generated source code 224A and 224B(collectively “generated source code 224”). Application resources 220may represent information that specifies the predefined features (e.g.,declared features and permissions) of an application, such as thefeatures of an application user interface (e.g., design layout, objects,colors, and other predefined features). In contrast to applicationresources 220, application source code 226 by definition represents theprogram logic within an application or target. For example, whileapplication resources 220 may define the shape, color, or style of anobject in a user interface of an application, application source code226 may define the operations performed by a computing device when auser interacts with the object.

In some instances, application resources 220 may be defined in a mark-uplanguage (e.g., extensible markup language [XML], etc.) and applicationresources 226 may be defined in a general-purpose or object-orientedprogramming language (e.g., Java, C, etc.). Builder module 108 mayperform various resource assembly 262 tasks on application resources 220in order to translate and specify the predefined features of theapplication in a similar general-purpose or object-oriented programminglanguage that is used to define the logical features of the applicationthat are specified by application source code 226. For example, an assetpackaging tool of builder module 108 may assemble resources 220 andoutput generated source code 224 to specify the predefined features ofthe application in a language that is reconcilable, at compile time,with the logical features of the application defined by applicationsource code 226.

Builder module 108 may perform source compilation 264A of generatedsource code 224A and application source code 226 to produce virtualmachine (VM) code 228A. VM code 228A may be machine readable, executablecode, that may be interpreted and executed by (e.g., a virtual machinemodule executing at) one or more processors of a computing device, suchas test environment system 124. For example, in the Java programminglanguage, .class files are examples of VM code 228A. Builder module 108may perform source compilation 264A of generated source code 224A andapplication source code 226 by translating and reconciling thegeneral-purpose or object-oriented programming language instructionsassociated with code 224A and 226 into VM code 228A that can later beinterpreted and executed by a virtual machine.

In some examples, builder module 108 may perform source compilation 264Bof VM code 228A to produce virtual machine (VM) code 228B that isdifferent than VM code 228A. For instance, some computing platforms mayexist as a customized adaptation of a pre-existing computing platform.While a pre-existing computing platform may be suitable for someapplications, some mobile computing and/or wearable computing platformsmay offer various enhancements in execution and performance that requiredifferent VM code and/or a completely different virtual machineexecuting on underlying hardware to execute the different VM code.Builder module 108 may perform source compilation 264B of VM code 228Ato translate and redefine VM code 228A into machine readable, executableVM code 228B, that may be interpreted and executed by a differentvirtual machine module than the virtual machine module that can executeVM code 228A.

In some examples, builder module 108 may receive as input, any thirdparty virtual machine code 230 that may need compiling when buildermodule 108 performs source compilation 264B of VM code 228A. Forexample, builder module 108 may compile VM code 228A into VM code 228Bby further compiling any publicly available or other third party VM code230 that a developer has instructed builder module 108 to include in theVM code 228B build stage.

As shown in FIG. 2, target set 239 may include VM code 228A and/or 228B,resource data 224B, and other resources 236. Other resources 236generally represent any “non-compiled” resources (e.g., images, etc.)that were not compiled at resource assembly 262. Target set 239 mayrepresent the contents of an application. In accordance with techniquesof this disclosure, builder module 108 may determine at decision block267 whether the application package that includes target set 239 wasalready initially generated. For instance, if builder module 108 has notpreviously generated the application package in a programming session ofthe software developer, builder module 108 may target set 239 to producea single application package 238. In some examples, a programmingsession may be continuous period of time in which the software developerbegins programming and later ceases programming to perform otheractivities without returning to programming during the continuous periodof time.

In some examples, after builder module 108 builds application package238, builder module 108 may perform additional operations deployingapplication package 238 for subsequent execution, such as at testenvironment system 124 of FIG. 1. For example, in some instances,builder module 108 may preform debug and/or release signing 270 ofapplication package 238 to create signed application package 242. Thatis, before installation of the contents of application package 238, somecomputing environments may require the contents to have an identifier(e.g., a bit, a digital signature, a certificate, or some other marking)marking the author (e.g., the developer) of the contents as well asinformation specifying the contents as either being a debug or releasedversion of the application. Builder module 108 may digitally sign thecontents of application package 238 with an indication that the contentsare either a debug or release version and output the marked contents assigned application package 242.

In some instances, builder module 108 may align 272 signed applicationpackage 242 to create signed and aligned application package 244 beforeuploading or otherwise releasing application package 244 for laterexecution by one or more computing devices, such as test environment 124of FIG. 1. For example, builder module 108 may perform alignment 272 ofsigned application package 242 to ensure that all uncompressed dataassociated with package 242 begins with a particular (memory) alignmentrelative to the beginning of the file. For instance, by performingalignment 272, builder module 108 may causes all uncompressed datawithin package 242, such as images or other uncompressed files, to bealigned on two-byte, four-byte, or other byte-level boundaries. In thisway, all portions of package 244 can subsequently be accessed directlywith a memory call, even if some portions contain binary data withalignment restrictions. By aligning signed application packages 242,builder module 108 may enable a computing device to execute applicationpackage 244 using less memory. Upon generating signed and alignedapplication package 244, builder module 108 may deploy or send 276package 244 to a computing environment such as test environment system124.

Returning to decision block 267, if builder module 108 determines thatan application package for target set 239 has been previously generatedand deployed to a test environment system, builder module 108 maydetermine which compiled targets have changed within target set 239 as aresult of incremental modifications to a subset of the source codeand/or resources. For instance, builder module 108 may determine whetheran updated compiled target that was generated by builder module 108 morerecently than an existing version of a compiled target differs from theexisting version. Change detection module 110 may select the updatedcompiled targets and resources that have changed as target subset 243.Builder module 108 may deploy or send 276 the target subset 234 to acomputing environment, such as test environment system 124. In someexamples, builder module 108 deploys or sends target subset 243 whilerefraining from deploying other compiled targets and/or resources intarget set 239 that are not included in target subset 243. In this way,only the updated target subset 243 of resources and compiled targets issent to test environment system 124.

FIG. 3 is a block diagram illustrating builder computing device 102 asan example computing device configured to perform an example softwarecompilation and build process, in accordance with one or more aspects ofthe present disclosure. FIG. 3 illustrates only one particular exampleof builder computing device 102 and other examples of builder computingdevice 102 may exist. Builder computing device 102 of FIG. 3 may includea subset of the components included in builder computing system 102 ofFIG. 1 and may include additional components not shown in FIG. 3.Builder computing device 102 may perform process 200 of FIG. 2.

In the example of FIG. 3, builder computing device 102 may be a desktopcomputing device although in other examples, builder computing device102 may be a laptop, tablet computing device, server computing device orany other computing device capable of performing techniques of thisdisclosure. Builder computing device 102 may be a software developmentdevice configured to compile code as part of a build process (e.g.,process 200 of FIG. 2) for creating one or more executable softwareapplications, such as an application package.

As shown in the example of FIG. 3, builder computing device 102 includesone or more processors 340, one or more input components 342, one ormore output components 344, one or more communication components 346,and one or more storage components 348. Storage components 348 ofbuilder computing device 102 includes builder module 108, target set112, insertion module 352, debugger 117, command module 352, changedetection module 110, compiler 114, preprocessor 116, deploy module 356,packaging module 358, verifier module 360, swap heuristics 362, testenvironment, 364, source code 118, editor 106, and resources 120.

Communication channels 350 may interconnect each of the components 340,342, 344, 346, and 348 for inter-component communications (physically,communicatively, and/or operatively). In some examples, communicationchannels 350 may include a wired and/or wireless system bus, a wiredand/or wireless network connection, an inter-process communication datastructure, or any other method for communicating data between internalcomponents of builder computing device 102.

One or more input components 342 of builder computing device 102 mayreceive input on behalf of the various other components and modules ofbuilder computing device 102. For example, keyboard input from a user ofdevice 102 at a text editor for writing application source code 326and/or application resources 320. Examples of input are tactile, audio,and video input. Input components 342 of builder computing device 102,in one example, includes a presence-sensitive display, a touch-sensitivescreen, a mouse, a keyboard, a voice responsive system, a video camera,a microphone or any other type of device for detecting input from ahuman or machine.

One or more output components 344 of builder computing device 102 maygenerate output for receipt by other computing devices, systems, and auser of device 102. For example, one or more output components 344 maypresent a user interface of a text editor and/or integrated developmentenvironment at a display of output components 344 from which a user ofdevice 102 can view application source code 326 and/or applicationresources 320. Examples of output are tactile, audio, and video output.Output components 344 of builder computing device 102, in one example,includes a presence-sensitive display, sound card, video graphicsadapter card, speaker, cathode ray tube (CRT) monitor, liquid crystaldisplay (LCD), light emitting diode (LED) display, organic lightemitting diode (OLED) display, or any other type of device forgenerating output to a human or machine.

One or more communication units 346 of builder computing device 102 maycommunicate with external devices via one or more wired and/or wirelessnetworks by transmitting and/or receiving network signals on the one ormore networks. Examples of communication unit 346 include a networkinterface card (e.g. such as an Ethernet card), an optical transceiver,a radio frequency transceiver, a GPS receiver, or any other type ofdevice that can send and/or receive information. Other examples ofcommunication units 346 may include short wave radios, cellular dataradios, wireless network radios, as well as universal serial bus (USB)controllers.

One or more processors 340 may implement functionality and/or executeinstructions within builder computing device 102. For example,processors 340 on builder computing device 102 may receive and executeinstructions stored by storage components 348 that execute thefunctionality of modules 106, 108 (and corresponding data and modules ofbuilder module 108), and test environment system 364. These instructionsexecuted by processors 340 may cause builder computing device 102 tostore information within storage components 348 during programexecution. Processors 340 may execute instructions of modules 106, 108(and corresponding data and modules of builder module 108), and testenvironment system 364 to cause modules 106, 108 (and corresponding dataand modules of builder module 108), and test environment system 364 toperform techniques of this disclosure. That is, modules 106, 108 (andcorresponding data and modules of builder module 108), and testenvironment system 364 may be operable by processors 340 to performvarious actions or functions of builder computing device 102 inaccordance with techniques of this disclosure.

One or more storage components 348 within builder computing device 102may store information for processing during operation of buildercomputing device 102 (e.g., builder computing device 102 may store dataaccessed by 106, 108 (and corresponding data and modules of buildermodule 108), and test environment system 364 during execution. In someexamples, storage component 348 is a temporary memory, meaning that aprimary purpose of storage component 348 is not long-term storage.Storage components 348 on builder computing device 102 may be configuredfor short-term storage of information as volatile memory and thereforenot retain stored contents if powered off. Examples of volatile memoriesinclude random access memories (RAM), dynamic random access memories(DRAM), static random access memories (SRAM), and other forms ofvolatile memories known in the art.

Storage components 348, in some examples, also include one or morecomputer-readable storage media. Storage components 348 may beconfigured to store larger amounts of information than volatile memory.Storage components 348 may further be configured for long-term storageof information as non-volatile memory space and retain information afterpower on/off cycles. Examples of non-volatile memories include magnetichard discs, optical discs, floppy discs, flash memories, or forms ofelectrically programmable memories (EPROM) or electrically erasable andprogrammable (EEPROM) memories. Storage components 348 may store programinstructions and/or information (e.g., data) associated with modules106, 108 (and corresponding data and modules of builder module 108),test environment system 364, source code 118, and resources 120.

Modules 106, 108 (and corresponding data and modules of builder module108), and test environment system 364 may perform operations usingsoftware, hardware, firmware, or a mixture of hardware, software, and/orfirmware residing in and executing on builder computing device 102.Builder computing device 102 may execute modules 106, 108 (andcorresponding data and modules of builder module 108), and testenvironment system 364 with a single or multiple processors, such asprocessors 340. Builder computing device 102 may execute one or more ofmodules 106, 108 (and corresponding data and modules of builder module108), and test environment system 364 as a virtual machine (VM)executing on underlying hardware components of builder computing device102. In some examples, modules 106, 108 (and corresponding data andmodules of builder module 108), and test environment system 364 may bearranged remotely to, and remotely accessible from, builder computingdevice 102, for instance, as one or more network services accessible bybuilder computing device 102 via a network cloud.

Builder module 108 is a more detailed example of builder module 108 ofFIG. 1. Builder module 108 may perform the same, additional, or feweroperations than those performed by builder module 108 in FIG. 1. Forexample, builder module 108 may perform process 200 of FIG. 2, a subsetof process 200, or additional operations beyond process 200.

The techniques of FIGS. 1 and 2 are further described with the previousexample of FIG. 1. Source code 118, as shown in FIG. 2, may include asource file that includes source code defining a USER class as describedin FIG. 1. The source file that defines the USER class may include threevariables: id, firstName, and lastName. The USER class may also includethree methods: setFirstName, setLastName, and getFullName. As anexample, the method setFirstName (String first) may be a method of aclass (e.g., USER) defined in the source file.

Initially, test environment system 124 may not include an applicationpackage for application 130 and builder computing system 102 may notinclude target set 112. To compile application 130 for the first time ina programming session, a software developer may provide a user inputthat causes builder module 108 to build and deploy application 130 in aninitial build and deploy iteration. For instance, builder module 108 mayinclude command module 354. Command module 354 may receive indicationsof user input from input components 342. For instance, if a user selectsa visual icon in IDE 104 that corresponds to building and deploying anapplication, command module 354 may receive data that represents theuser's selection to build and deploy the application. In other examples,if a user selects an icon in IDE 104 that corresponds to debugging anapplication, command module 354 may receive data that represents theuser's selection to debug the application. In the example of FIG. 3,command module 354 receives data that represents the user's selection tobuild and deploy the application.

In response to receiving the indication of user input to build anddeploy the application, command module 354 may send data to preprocessor116 to perform any preprocessing operations on source code 118 andresources 120. Preprocessor 116 may determine a subset of source codefiles 118 and/or a subset of resources 120 that correspond toapplication 130 based, for example, on names of sources files and/orresources, or a project name or working set that specifies that sourcefiles and/or resources for application 130. Upon preprocessor 116performing any preprocessing operations on source code 118 and resources120, compiler 114 may compile source code from the sources files and anyresources that may be compiled. For instance, compiler 114 may transformthe human-readable source code for application 130 into machine-readablecode, such as a set of compiled targets.

Builder module 108 may also include an insertion module 352. Uponcompiler 114 generating the compiled targets, insertion module 352 mayadd program logic in the form of bytecode to compiled targets, where theprogram logic performs the functionality of lines 2-6 of the pseudocodedescribed in FIG. 1. Insertion module 352, for instance, may add a$changeLocal variable to an object definition (e.g., compiled target)that is compiled from the USER class in the source file. Insertionmodule 352 may include the $changeLocal variable to store a reference ormemory location to another, but more recent version, of an objectdefinition of the same type of USER class later during execution in testenvironment system 364.

Insertion module 352 may include additional program logic similar tolines 2-6 as in the description of FIG. 1 to each method of the classUSER, such as setFirstName, setLastName, and getFullName. Insertionmodule 112 may include each compiled target, following injection of thebytecode with the additional program logic, in target set 112. In someexamples, change detection module 110 determines whether builder module108 has previously generated an application package that representsapplication 130.

In accordance with techniques of this disclosure, if change detectionmodule 110 determines that application 130 has not been previouslybuilt, then builder module 108 may generate an application package thatrepresents application 130 and includes the contents of target set 112.Packaging module 112, for instance, may assemble compiled targets anduncompiled targets (e.g., resources) of target set 112 into anapplication package. In some examples, the application package may becompressed and/or may include one or more configuration files thatindicate the contents and/or structure of the application package. Insome examples, packaging module 358 may sign the application packagewith a key to indicate the authenticity of the package as beinggenerated by a particular author. Deploy module 356 may deploy orotherwise send the application to test environment system 364. In someexamples, deploy module 356 may include program logic to communicatewith a server included in test environment system 364. For instance,deploy module 356 may create a socket to communicate with a server intest environment system 364. The server in test environment system 364may receive an application package from builder computing system 102,and in some examples, initiate execution of the application package. Theserver in test environment system 364 may initiate execution of theapplication package in response to one or more commands sent by deploymodule 356 to the server in test environment system 364.

In contrast to test environment system 124 of FIG. 1, test environmentsystem 364 may be an emulator of a device implemented at buildercomputing system 102, rather than a standalone computing device. Forinstance, test environment system 364 may simulate a set of hardware(e.g., processors, input components, output components, andcommunication components) executing an operating system. Testenvironment system 364 may further include one or more system runtimes,such as system runtime 138 in FIGS. 1 and 4, which may provide one ormore libraries, loaders, resource managers, servers, or other componentsto execute an application, such as application 130.

As described in FIG. 1, at a later time, the software developer maychange functionality in the method getFullName by altering the sourcecode for getFullName in a source file of source code 118. The softwaredeveloper may provide another user input, received by command module354, to rebuild application 130. Command module 354 may receive the userinput and cause preprocessor 116 to perform any preprocessing on sourcecode 118 and/or resources 120. Compiler 114 compiles the altered sourcecode for getFullName. In some examples, compiler 114 may query changedetection module 110 to determine which other sources files have beenpreviously compiled. In this way, if compiler 114 determines that asource file has not changed and corresponding compiled target alreadyexists for the source file, then compiler 114 may not re-compile thesource file. In other examples, compiler 114 may compile re-compile allsource files for application 130.

Upon compiler 114 compiling the source files, insertion module 352 mayquery change detection module 110 to determine whether an existingcompiled target corresponding to the USER class is in target set 112.Insertion module 352, upon determining that a previous compiled targetcorresponding to the USER class exists, may insert or otherwise includeinformation in the updated compiled target that indicates the compiledtarget is changed from the existing compiled target. For instance,insertion module 352 may modify the class name, method names, and/orvariable names within the updated compiled target to distinguish theclass name, method names, and/or variable names from an existingcompiled target of the same type. As an example, insertion module 352may change the class name included in the updated compiled target toUSER$override. That is, insertion module 352 may inject bytecode orotherwise modify the updated compiled target to add the suffix $overrideto the existing USER class name. Although $override is used forillustrations purposes, any suitable prefix, suffix or substring may beprepended, inserted, or appended to existing names, such as class name,method name, and/or variable name. In some examples, insertion module352 may inject bytecode or otherwise modify the updated compiled targetto add an additional argument to each method signature of the USERclass. As described in FIG. 1, the additional argument is a reference toan instance of the compiled target that called method. For instance,insertion module may rewrite getFullName (Object obj, int id) in theupdated compiled target.

After compiler 114 has compiled a new version of the USER class into theupdated compiled target, and insertion module 352 has added theadditional program logic, change detection module 110 may determinewhich resources and/or compiled targets have been updated. Becausebuilder module 108 previously deployed the entire application packagefor application 130 to test environment system 364, builder module 108may refrain from performing unnecessary activities such as re-packaging,signing, aligning, an entirely new application package, and insteaddetermine a target subset of only those resources and/or updatedcompiled targets that have changed. For instance, change detectionmodule 110 may determine whether an updated compiled target that wasgenerated by builder module 108 more recently than an existing versionof a compiled target differs from the existing version. Change detectionmodule 110 may select the updated compiled targets and resources thathave changed as a target subset.

In some examples, packaging module 358, rather than generating a newapplication package with all of target set 112 that representsapplication 130, may instead send the target subset to test environment354. In some examples, package module 358 may send individual changedcompiled targets and/or resources to deploy module 356, which may inturn send the individual changed compiled targets and/or resources totest environment system 364. In other examples, packaging module 358 maygroup the changed compiled targets and/or resources of the target subsetinto a single file, which deploy module 356 may send to test environmentsystem 364. As described in FIG. 1, builder module 108 may deploy orsend the target subset while refraining from deploying other compiledtargets and/or resources in the target set that are not included intarget subset. In this way, only the updated target subset of resourcesand compiled targets may be sent to test environment system 124.

Upon receiving the target subset, test environment system 364 may loadthe updated compiled target for the USER class into memory while theprevious version of the compiled target is already loaded in memory forexecution of application 130. Test environment system 364, when loadingthe updated compiled target into memory, may determine a memory locationof or reference to the newer version of the updated compiled target, andstore this memory location or reference in the $change variable of theprevious version of the object definition. For instance, testenvironment system 364 may use reflection to identify and set the$change variable of the previous version of the object definition. Inthis way, if application 130 executes setFirstName (String first), theprevious version of the compiled target initially executes itssetFirstName (String first) method and determines that ($changeLocal!=null) is true because the $changeLocal variable is set to the memorylocation or reference to the updated version of the compiled targetbased on the $change variable. As a result, the previous version of thecompiled target executes $changeLocal.access$dispatch ( ). Theaccess$dispatch ( )method includes dispatcher program logic that acceptsthe arguments ($changeLocal, “setFirstName (String first)”, first). Thedispatcher program logic accesses the updated compiled target based onthe reference included in $changeLocal. Upon accessing the updatedcompiled target, the dispatcher executes the method named “setFirstName(String first)”, using the argument first. Because the dispatcherprogram logic can access the updated compiled target using the$changeLocal variable while application 130 is executing, changes infunctionality to the updated compiled target may be tested and observedwithout terminating execution of application module 130. Such techniquesmay be referred to as “hot-swapping.” Since the execution of applicationmodule 130 has not been terminated, the objects state for existingobject instances may remain accessible in memory. As such, changes tothe updated compiled target can be tested and observed using theexisting object instances.

In some examples, techniques of this disclosure may be applied toobject-oriented programming languages such as Java in which aconstructor of a subclass may call a super ( ) method, which invokes aconstructor of the parent class. In some examples, the parent class mayinclude multiple constructors that each includes signatures that havedifferent types and/or numbers of arguments. For instance, a parentclass A may include a first constructor A (String s) and a secondconstructor A (int n).

If hot-swapping techniques were applied such that an original compiledtarget (e.g., subclass B) included call to A (String s) and wasreferenced by an updated compiled target (e.g., subclass B) thatincluded a hard coded call to A (int n), then execution of the updatedcompiled target may fail using hot swapping as a result of a castexception. As such, the application may revert to cold-swappingtechniques to apply the updated call to A (int n), which may be slowerthan hot-swapping. To avoid reverting to cold swapping or failingaltogether, insertion module 352 may inject bytecode for a newconstructor represented by the following code of lines 2-11:

 1 class B extends A {  2 private B(MarkerType _(—) , StringsuperSignature, Object args[ ]) {  3 switch( superSignature ) {  4 case“<init>.(Ljava/lang/String;)V”:  5 super((String)args[0]);  6 break;  7case “<init>.(I)V”:  8 super((int)args[1]);  9 break; 10 default: 11throw new InstantReloadException( ); 12 }

In line 2, insertion module 352 has generated a constructor signaturethat includes the argument MarkerType_which operates as a placeholder toavoid namespace collisions with existing constructor signature. TheString superSignature indicates a string that identifies whichparticular super constructor will be called at runtime. The Object args[ ] argument includes the arguments that would be passed to the superconstructor that will be called at runtime.

At line 3, a switch statement matches the string that identifies whichparticular super constructor will be called at runtime to a particularcase of the switch statement. As shown in lines 4 and 7, the twopossible strings in this example are “<init>. (Ljava/lang/String;) V”and “<init>. (I) V”. The generation of these strings that identify whichparticular super constructor will be called at runtime are furtherdescribed below in this example. The syntax of the “<init>.(Ljava/lang/String;) V” is as follows. The <init> string indicates thatthe “<init>. (Ljava/lang/String;) V” string represents a particularconstructor. The Ljava/lang/String; string indicates that the argumentto the constructor is of type string, and the v indicates that thereturn type of the method is void (e.g., because the constructor doesnot return any values). If superSignature includes a value of “<init>.(Ljava/lang/String;) V” then super constructor A (String s) will beexecuted at runtime by the updated compiled target. Alternatively,superSignature includes a value of “<init>. (I) V” then superconstructor A (int n) will be executed at runtime by the updatedcompiled target, where (I) represents an integer argument of the superconstructor for A (int n).

In addition to the code above, insertion module 352 may include bytecodein the existing constructor of class B (e.g., a subclass of class A)that is represented by the following code of lines 2 and 4-8:

1 B( ) { 2 if ($change == null) { 3 super(100); 4 } else { 5 StringsuperSignature = change.access$dispatch( 6 “init$super _(—) sig”,newObject[ } { $signatureOfThis }); 7 this((MarkerType)null,superSignature, locals); 8 } 9 }As shown in line 2, insertion module 352 checks whether an updatedversion of the compiled target (e.g., class B) exists, and if not, thesuper constructor with the integer value 100 is executed, which causesparent class A to execute the constructor of class A that accepts aninteger argument. If, however, an updated version of the compiled target(e.g., class B) exists, the code in lines 4-8, which was injected asbytecode by insertion module 352, is executed. Specifically, lines 5-6generate a string—either “<init>. (Ljava/lang/String;) V” or “<init>.(I) V”—based on the “init$super_sig” which instructs thechange.access$dispatch to return one of the two possible strings. The$signatureOfThis may indicate the type of super constructor of parentclass A that will be called and for which change.access$dispatch willgenerate either the string “<init>. (Ljava/lang/String;) V” or “<init>.(I) V”. The generated string is then used in line 7 to call the newlyadded constructor as described in lines 1-12 above to call the selectedsuper constructor of parent class A. In this way, even if an updatedversion of the compiled target (e.g., class B) calls a different superconstructor of A, the inserted bytecode representing source code lines1-12 and 1-9 above enables the updated version of the compiled target(e.g., class B) to execute the appropriate super constructor of A usinghot-swapping techniques of this disclosure rather than cold-swapping orfailing altogether.

In some examples, structural changes implemented by a software developerto source code in application 130 may not allow application 130 toexecute updated compiled targets in test environment system 364 withoutrestarting application 130. For instance, application 130 may execute asone or more processes and/or threads in test environment system 124, andrestarting application 130 may include terminating processes and threadsof application 130 in test environment system 124. Restartingapplication 130 may include terminating all processes and threads ofapplication 130 and subsequently initiating execution of application130. Examples of such structural changes may include changinginheritance hierarchies in a hierarchy of classes in an object-orientedapplication, although many other examples are possible. More generally,structural changes that do not permit or allow application 130 toexecute updated object definition 144B without restarting application130 may include changes to source code that do not support byte-codeinjection or permit modification of compiled targets.

Builder module 108 may implement techniques to send a target subset ofcompiled and/or uncompiled targets that have changed to test environmentsystem 364 and enable application 130 to restart and execute with thechanged targets without re-packaging an entirely new application packageand deploying the new application package to test environment system364. Such techniques may be referred to as “cold-swapping.” Compiler 114and/or packaging module 358 may insert code or modify one or morecompiled or uncompiled targets within the application package thatrepresents application 130, such that application 130 is loaded intomemory with newer compiled and uncompiled targets being loaded first inreverse chronological order. For instance, builder module 108 mayinclude a customer classloader as the inserted code that loads newercompiled and uncompiled targets first in reverse chronological order, orthe customer class loader may be included in system runtime 138, asshown in FIG. 4. If a more recent version of a compiled or uncompiledtarget has been loaded into memory, the older version may be not beloaded into memory, thereby ensuring that newer versions of compiled anduncompiled targets are loaded into memory.

To provide for cold-swapping, when application 130 is loaded by a loader(e.g., loader 454 in FIG. 4) in test environment system 364, the loadermay search for and load newer compiled and uncompiled targets beforeolder compiled and uncompiled targets. In some examples, compiledtargets with machine executable code are stored in a predefined locationor directory in a filesystem of test environment system 124 or 364. Thepredefined location or directory may be a relative or absolutedirectory. Compiler 114 and/or packaging module 358 may include datawithin the application package for application 130 that identifies thepredefined location or directory.

To further describe cold-swapping techniques, builder module 108 mayinitially build an application package for application 130 that includestarget set 112 as described in FIG. 3. Compiler 114 and/or packagingmodule 358 may insert code or modify one or more compiled or uncompiledtargets within the application package that represents application 130,such that application 130 is loaded into memory with newer compiled anduncompiled targets being loaded first in reverse chronological order.Test environment system 364 may execute application 130 initiallythereby loading one or more compiled and/or uncompiled targets intomemory. Test environment system 364 may store the compiled targets withmachine executable code in the predefined location or directory of testenvironment system 364 that is specified by the application package therepresents application 130.

At a later time, a software developer may update source code forapplication 130 in such a way that does not allow application 130 toexecute updated compiled targets in test environment system 364 withoutrestarting application 130. Builder module 108 may compile the updatedsource code into one or more updated compiled targets of a hot-swaptarget subset as described above in FIG. 3, which include identifierssuch as $override to indicate that the compiled targets have changed.Builder module 108 may also compile the updated source code into one ormore updated compiled targets of a cold-swap target subset, whichinclude compiled and uncompiled targets, based on the source codechanges, that compiled according to the initial, rather than subsequent,compilation process as described above in FIG. 3.

In some examples, builder module 108 may send the hot-swap target subsetand/or the cold-swap target subset to test environment system 364.Builder module 108 may send the hot-swap target subset and/or thecold-swap target subset while application 130 is executing. Textenvironment system 364 may store the hot-swap target subset and/or thecold-swap target subset targets in the predefined location or directoryinitially specified in application package representing application 130.In some examples, builder module 108 may send a command with thehot-swap target subset and/or the cold-swap target subset targets thatis received by test environment system 364. Test environment system 364may, based on the command (e.g., specifying a cold-swap operation),terminate one or more processes of application 130 and re-executeapplication 130.

Upon initiating re-execution of application 130, the loader forapplication 130 may identify cold-swap target subset of compiled targetsincluded in the predefined location or directory initially specified inapplication package representing application 130. The loader maydetermine that an older version and newer version (e.g., from thecold-swap target subset) of a compiled target exist in the predefinedlocation or directory. The loader may identify the newer version of thecompiled target based on a date, timestamp, version number or otheridentifier that indicates the newer compiled target is more recent thanthe older compiled target. Based on this determination, the loader mayload the newer compiled target first into memory. In this way,application 130 may execute using the newer compiled target that wasloaded into memory.

As described above, cold-swapping may reduce the amount of time neededto perform a subsequent build and deploy iteration because the targetsubset of updated compiled targets, rather than an entirely newapplication package, is deployed at test environment system 364 in asubsequent iteration. Since application 130 includes data to identifythe predefined location or directory for compiled targets that includemachine-executable code and load such compiled targets in reversechronological order, application 130 may be restarted with the newestcompiled targets being loaded into memory for execution.

In some examples, builder module 108 may perform one or more patchcompaction techniques. Each time builder module 108 detects edits tosource files, compiles the changes into updated compiled targets, andthen pushes updated compiled targets to the device, the test environmentsystem may add a new patch file, comprising the updated compiledtargets, into the predefined location or directory that is known toapplication 120. That is, each patch file may include a different set ofupdated compiled targets. At startup, application 130 will add allpatches for application 130 to its loader (e.g., loader 454 in FIG. 4),in reverse order, such that the most recent compiled target is found bythe loader first, and therefore loaded and used by application 130.However, for extended periods of iterative development, this may resultin many patches, all being added to the test environment system. Thismay make subsequent executions of application 130 at test environmentsystem 124 take longer and application 130 may run slower.

To avoid this, insertion module 352 and/or packaging module 358 may addruntime code to the application package representing application 130that performs patch compaction. When a new patch (e.g., updated set ofcompiled targets) is received at test environment system 124, the patchcompaction runtime code previously added to the application package willperform patch compaction. To illustrate, for each patch file, the patchcompaction runtime code of application 130 stores an index of thecompiled targets contained within the patch. The patch compactionruntime code can quickly traverse through a set of patch indices, inreverse order, and keep track of which compiled targets or classes arediscoverable from a given patch by the loader (e.g., class loader) forapplication 130. In some examples, the indices may be stored in anysuitable data structure such as a graph, map, list, or the like. In themost recent patch file, every class or compiled target of a specifictype is available. In a prior patch, only classes or compiled targets ofthe specific type that are not also available in the later patch areaccessible, and so on. Any patch that does not have any classes orcompiled targets not present in later patches, may not be used byapplication 130, and can therefore be removed. As such, the patchcompaction runtime code of application 130 may delete or otherwiseremove any patch that does not have any classes or compiled targets notpresent in later patches. This may save space and improve performancewhen executing application 130. In practice this may beneficial becauseit may be typical for a user to make multiple edits to the same sourcefile, over and over, and in such cases only the last patch needs to bepreserved at test environment system 124.

As an additional performance improvement, in Java or other similarlanguages, there are often inner classes, which show up as separateclasses even though they are in the same compilation unit. Edits tocompilation units occur at the compilation unit level (the source file),rather than the individual classes, which may reduce the number ofchecks for class overlaps, but may also have the benefit that if theuser removes an inner classes, a later patch will not see the removedinner class and consider that earlier patch relevant just because itcontains an inner class reference that is not present in the laterpatch.

Builder module 108 may implement techniques to send a target subset ofcompiled and/or uncompiled targets that have changed to test environmentsystem 364 and restart one or more threads of application 130 (withoutrestarting application 130 completely, i.e., terminating all processesand subsequently initializing execution) in order to execute the changedcompiled and/or uncompiled targets. Such techniques may be referred toas “warm-swapping.”

In some examples, builder module 108 may determine that one or more ofresources 120 may have changed during a build iteration. For instance, asoftware developer may have added or updated an image that is includedin application 130. The image may be an uncompiled target because theimage is not compiled by compiler 114 but is included in target set 112.Rather than re-compiling and re-packaging an application package forapplication 130 each time that one or more of resources 120 changes,builder module 108 may implement “warm-swapping” techniques in whichapplication 130 may be updated with the one or more changed resourceswithout restarting application 130 entirely.

As an example of warm-swapping, builder module 108 may initially buildan application package that includes target set 112 which may includecompiled and uncompiled targets, as previously described above. Forinstance, target set 112 may include an uncompiled resource, such as animage that is used by application 130. Builder module 108 may deploy theapplication package as described above when an application package isinitially deployed in test environment system 364. The applicationpackage may include target set 112, which includes the compiled anduncompiled resources. Test environment system 364 may executeapplication 130 and load one or more compiled and uncompiled resourcesinto memory, including the image. More particularly, as further shown inFIG. 4, a test environment, such as test environment system 124 mayinclude a resource manager, such as resource manager 460. Resourcemanager 460 may be a module that provides one or more applicationprogramming interfaces to applications executing at test environmentsystem 124. Applications may invoke the APIs directly or indirectlythrough libraries 458 to load uncompiled targets, such as an image fordisplay or use in application 130. In some examples, a test environmentmay have a single resource manager instance per application or per testenvironment.

At a later time, a software developer may modify the image or replacethe image with a different image of the same file name. The softwaredeveloper may provide a user input that causes builder module 108 tobuild and deploy application 130. Change detection module 110 maydetermine that the original image has been modified and include theupdated image as part of a target subset, which builder module 108 sendsto test environment system 364. Test environment system 364 may receivethe target subset.

In some examples of warm-swapping, resources are stored in a predefinedlocation or directory in a filesystem of test environment system 124 or364. The predefined location or directory may be a relative or absolutedirectory. The predefined location or directory for resources may bedifferent than or the same as the predefined location or directory forcompiled targets comprised of machine-readable code. In some examples, apredefined location may be hardcoded in a module or application by asoftware developer, or may be dynamically loaded from a configurationfile into a variable of the module or application. As furtherillustrated and described in FIG. 4, a resource manager may loaduncompiled targets such as resources from the predefined location ordirectory. The resource manager may load the resources based on dataspecifying the location or directory that is included in the resourcemanager or the application package. For instance, compiler 114 and/orpackaging module 358 may include data within the application package forapplication 130 that identifies the predefined location or directory.

The resource manager may execute as a process or thread. In someexamples, the resource manager may be a process that is forked from or athread that is created by another process or thread of application 130.In other examples, the resource manager may be a system process orthread is initiated outside the execution of application 130, but whichcommunicates with application 130 using one or more interprocesscommunication techniques. In any event, when test environment system 364receives the target subset, a coordinator module stores the resources inthe target subset in a temporary file or directory that is known thecoordinator module. For instance, as further described in FIG. 4, thecoordinator module (e.g., coordinator 459 in FIG. 4) may receive theresources from a server and store them in a temporary file or directorywith a name that is different than the predefined location or directorythat stores the resources and is known to the resource manager.

The coordinator may also receive a command to restart the resourcemanager without restarting application 130 entirely. Based on thecommand, the coordinator may swap the name of the predefined location ordirectory that stores the resources and is known to the resource managerand the name of the temporary file or directory that stores the updatedresources. For instance, the coordinator may rename the predefinedlocation or directory that stores the resources and is known to theresource manager to the name of the temporary file or directory thatstores the updated resources, and vice versa. Based on the swapping ofdirectory names, the coordinator may issue a signal or other instructionto the resource manager to restart the processor or thread thatimplements the resource manager. When the resource manager restarts,without terminating or restarting application 130 entirely, the resourcemanager opens the directory known to the resource manager, which nowincludes the updated resources. The newly-instantiated resource managermay reference the updated resources. In some examples, the coordinatormay use reflection to identify each compiled target that is alreadyloaded in memory and references the resource manager. The coordinatorupdates any such references to the newly-instantiated resource manager,which contains references to the updated resources. The coordinator mayuse reflection to update these references thereby avoiding thetermination of application 130 entirely. In this way, application 130may exhibit or otherwise display the updated resources without entirelyrestarting application 130.

In some examples, resource changes trigger code changes as well. Forexample, dragging in a button user interface element in a layout editormay only edit the layout .xml file, but it may set a new and unique “id”attribute on the button, such as @+id/button. Some resource systems(e.g., Android) may convert this into a special R.id.button field, andshift a number of unique ids on existing R fields. The positions of theR bits in a resource field that identifies/references a resource aretied to these new values, so builder module 102 may update all codereferences to R.type fields as well.

In some examples, an IDE that includes or communicates with buildermodule 108 may include a “run” icon that, when selected, causes buildermodule to initially build and deploy an application package, or if theicon is selected subsequent to builder module initially building anddeploying the application package, then builder module 108 may performhot-swapping and/or warm-swapping techniques. In some examples, theappearance of the run icon may change from a first visual appearancethat indicates builder module will initially build and deploy andapplication package to a second, different visual appearance that thebuilder module will perform hot-swapping and/or warm-swappingtechniques. The IDE may also include a “debugging” icon that operatesand appears in a similar manner as described with respect to the “run”icon, but performs debugging operations for the initially deployedapplication or performs debugging using hot-swapping and/orwarm-swapping.

In some examples, builder module 108 may include a verifier module 360and heuristics 362. Verifier module 360 may determine whether changes toone or more compiled targets permit hot- or warm-swapping or necessitateusing cold-swapping. Verifier module 360 may determine, based on datareceived from change detection module 110 and/or heuristics 362, whetherhot- or warm-swapping may be used in test environment system 364 for thechanges made in updated compiled targets.

Heuristics 362 may include data representing one or more conditions.Each condition may indicate whether hot- or warm-swapping can be used attest environment system 364. For instance, if changing inheritancehierarchies in a set of updated compiled targets would not permithot-swapping, heuristics may include a condition to test for changedinheritance hierarchies in either the source code or bytecode of theupdated compiled targets. If verifier module 360 determines that eitherthe changed source code or bytecode of the updated compiled targetssatisfies a condition in heuristics 362 that hot-swapping orwarm-swapping cannot be used, then verifier module 360 may send data topackaging module 358, which causes packaging module 358 to insert datawithin a target set or target subset that hot-swapping or warm-swappingcannot be used. If verifier module 360 determines that either thechanged source code or bytecode of the updated compiled targetssatisfies a condition in heuristics 362 that hot-swapping orwarm-swapping cannot be used, then verifier module 360 may send data todeploy module 356 to send a command that indicates hot-swapping orwarm-swapping cannot be used and/or that cold-swapping should be usedfor the updated target set. Heuristics 362 may be configured by asoftware developer, hardcoded, or learned based on previous failures ofhot-swapping or warm-swapping data received from test environment 364.

FIG. 4 is a block diagram illustrating test environment system 124 as anexample computing device configured to execute application 130, inaccordance with one or more aspects of the present disclosure. FIG. 4illustrates only one particular example of test environment system 124and other examples of test environment system 124 may exist. Testenvironment system 124 of FIG. 4 may include a subset of the componentsincluded in test environment system 124 of FIG. 1 and may includeadditional components not shown in FIG. 4.

In the example of FIG. 4, test environment system 124 may be a mobilecomputing device, such as a smartphone or tablet, although in otherexamples, test environment system 124 may be a desktop, laptop, servercomputing device, virtual machine, emulator, or any other computingdevice or simulator of a computing device capable of performingtechniques of this disclosure. In examples where test environment system124 is an emulator or virtual machine, hardware components describedwith respect to test environment 124 in FIG. 4 may be emulated insoftware with similar functionality described with respect to thehardware of FIG. 4. Test environment system 124 may be a user computingdevice configured to execute one or more application packages, modulesor any other computer software.

As shown in the example of FIG. 4, test environment system 124 includesone or more processors 440, one or more input components 442, one ormore output components 444, one or more communication components 446,and one or more storage components 448. Storage components 448 of testenvironment system 124 includes, but is not limited to: application 130,object state 134, original object definition 144A, updated objectdefinition 144B, previous container 452A, original resources 136A,current container 452B, updated resources 136B, UI module 128, systemruntime 138, loader 454, server 456, libraries 458, and resource manager460.

Communication channels 450 may interconnect each of the components 440,442, 444, 446, and 448 for inter-component communications (physically,communicatively, and/or operatively). In some examples, communicationchannels 450 may include a wired and/or wireless system bus, a wiredand/or wireless network connection, an inter-process communication datastructure, or any other method for communicating data between internalcomponents of test environment system 124.

One or more input components 442 of test environment system 124 mayreceive input on behalf of the various other components and modules oftest environment system 124. For example, input components 442 mayreceive touch input from a user of test environment system 124. Examplesof input are tactile, audio, and video input. Input components 442 oftest environment system 124, in one example, includes apresence-sensitive display, a touch-sensitive screen, a mouse, akeyboard, a voice responsive system, a video camera, a microphone or anyother type of device for detecting input from a human or machine.

One or more output components 444 of builder test environment system 124may generate output for receipt by other computing devices, systems, anda user of test environment system 124. For example, one or more outputcomponents 444 may present a user interface generated by application130. Examples of output are tactile, audio, and visual output. Outputcomponents 444 of test environment system 124, in one example, includesa presence-sensitive display, sound card, video graphics adapter card,speaker, cathode ray tube (CRT) monitor, liquid crystal display (LCD),light emitting diode (LED) display, organic light emitting diode (OLED)display, or any other type of device for generating output to a human ormachine.

One or more communication units 446 of builder test environment system124 may communicate with external devices via one or more wired and/orwireless networks by transmitting and/or receiving network signals onthe one or more networks. Examples of communication unit 446 include anetwork interface card (e.g. such as an Ethernet card), an opticaltransceiver, a radio frequency transceiver, a GPS receiver, or any othertype of device that can send and/or receive information. Other examplesof communication units 446 may include short wave radios, cellular dataradios, wireless network radios, as well as universal serial bus (USB)controllers.

One or more processors 440 may implement functionality and/or executeinstructions within test environment system 124. For example, processors440 on test environment system 124 may receive and execute instructionsstored by storage components 448 that execute the functionality ofmodules 130 (and corresponding data and modules of module 130), module128 and module 138 (and corresponding data and modules of module 138).These instructions executed by processors 440 may cause test environmentsystem 124 to store information within storage components 448 duringprogram execution. Processors 440 may execute instructions of modules130 (and corresponding data and modules of module 130), module 128 andmodule 138 (and corresponding data and modules of module 138) to causemodules 130 (and corresponding data and modules of module 130), module128 and module 138 (and corresponding data and modules of module 138) toperform techniques of this disclosure. That is, modules 130 (andcorresponding data and modules of module 130), module 128 and module 138(and corresponding data and modules of module 138) may be operable byprocessors 440 to perform various actions or functions of testenvironment system 124 in accordance with techniques of this disclosure.

One or more storage components 448 within builder test environmentsystem 124 may store information for processing during operation of testenvironment system 124 (e.g., test environment system 124 may store dataaccessed by modules 130 (and corresponding data and modules of module130), module 128 and module 138 (and corresponding data and modules ofmodule 138) during execution. In some examples, storage component 448 isa temporary memory, meaning that a primary purpose of storage component448 is not long-term storage. Storage components 448 on test environmentsystem 124 may be configured for short-term storage of information asvolatile memory and therefore not retain stored contents if powered off.Examples of volatile memories include random access memories (RAM),dynamic random access memories (DRAM), static random access memories(SRAM), and other forms of volatile memories known in the art.

Storage components 448, in some examples, also include one or morecomputer-readable storage media. Storage components 448 may beconfigured to store larger amounts of information than volatile memory.Storage components 448 may further be configured for long-term storageof information as non-volatile memory space and retain information afterpower on/off cycles. Examples of non-volatile memories include magnetichard discs, optical discs, floppy discs, flash memories, or forms ofelectrically programmable memories (EPROM) or electrically erasable andprogrammable (EEPROM) memories. Storage components 448 may store programinstructions and/or information (e.g., data) associated with modules 130(and corresponding data and modules of module 130), module 128 andmodule 138 (and corresponding data and modules of module 138).

Modules 130 (and corresponding data and modules of module 130), module128 and module 138 (and corresponding data and modules of module 138)may perform operations using software, hardware, firmware, or a mixtureof hardware, software, and/or firmware residing in and executing on testenvironment system 124. Test environment system 124 may execute modules130 (and corresponding data and modules of module 130), module 128 andmodule 138 (and corresponding data and modules of module 138) with asingle or multiple processors, such as processors 440. Test environmentsystem 124 may execute one or more of modules 130 (and correspondingdata and modules of module 130), module 128 and module 138 (andcorresponding data and modules of module 138) as a virtual machine (VM)executing on underlying hardware components of builder computing device102 as shown in FIG. 3. In some examples, modules 130 (and correspondingdata and modules of module 130), module 128 and module 138 (andcorresponding data and modules of module 138) may be arranged as one ormore network services accessible via a network cloud.

Test environment system 124 is a more detailed example of testenvironment system 124 of FIG. 1. Test environment system 124 mayperform the same, additional, or fewer operations than those performedby test environment system 124 in FIG. 1. In accordance with techniquesof the disclosure, test environment system 124 may initially receive anapplication package that represents application 130. For instance,deploy module 356 of FIG. 3 may establish a connection with server 456of FIG. 4. As shown in FIG. 4, test environment system 124 may includesystem runtime 138. System runtime 138 may include loader 454, server456, libraries 458, and resource manager 460. In some examples, systemruntime 138 generally provides a set of services and libraries that anapplication, such as application 130 may use to execute at testenvironment system 124. For instance, server 456 may provide a serviceto receive application packages, target sets and subsets, or any otherinformation from test environment system 124. Server 456 may implementone or more communication protocols, such as USB, HTTP, TCP/IP or anyother suitable protocols for exchanging information with one or moreother computing devices.

Server 456, upon receiving the application package for application 130may invoke one or more functions of loader 454 to execute one or morecompiled targets (e.g., object definitions) of application 130. Forinstance, server 456 may receive, in addition to the applicationpackage, one or more commands that server 456 may execute or forward toother components within test environment system 124. As an example,server 456 may receive a command with the application package to executeapplication 130. Accordingly, server 456 may send or use the command tocause loader 454 to execute one or more compiled targets of application130.

In some examples, loader 454 loads a compiled target into memory. Insome examples, loader 454 may represent multiple loaders, where eachloader is responsible for loading a different compiled target intomemory. Loader 454 may, for a particular compiled target, locatecorresponding libraries 458 used by the compiled target and load anysuch libraries into memory, such that the libraries are accessible tothe compiled target. In some examples, each application may have one ormore loaders, which may be included in system runtime 138 or within theapplication itself. In the example of FIG. 4, loader 454 may initiallyload original object definition 144A into memory with correspondinglibraries from libraries 458. Original object definition 144A may be aUSER class compiled by compiler 114 that includes the additional programlogic described in FIGS. 1-3, such as bolded lines 2-6 in the followingpseudocode:

 1 setFirstName (String first) {  2 Object $changeLocal = $change;  3 if($changeLocal != null) {  4 return$changeLocal.access$dispatch(($changeLocal,  5 “setFirstName(Stringfirst)”,first))  6 }  7 // methodName program logic  8 firstName =first;  9 10 // existing setFirstName program logic 11 ... 12 }

When application 130 is executed initially, the $change variable is nullor otherwise uninitialized because no updated USER class has yet beencompiled and deployed at test environment system 124. Application 130may cause multiple instances of object definition 144A to beinstantiated, where the state information for each instance of objectdefinition 144A is stored as objects state 134. As such, the originalobject definition 144A may perform operations on state information formultiple, different instances of object definition 144A.

At a later time, while application 130 is executing in test environmentsystem 124, a software developer may modify source code for thesetFirstName (String first) method. As described in FIGS. 1-3, buildermodule 108 may determine that the source code for the setFirstName(String first) method has changed. Builder module 108 may injectbytecode or otherwise modify the updated compiled target to add thesuffix $override to the existing USER class name to indicate thatprogram logic within the USER class has changed, specifically, withinsetFirstName (String first). As described in FIGS. 1-3, deploy module356 may send a subset of changed compiled targets and uncompiled targetsas a target subset to test environment system 124 rather than sendingthe entire target set in an application package that representsapplication 130.

In FIG. 4, server 456 receives the target subset initially. Server 456may also receive a command that instructs target environment system 124to apply the updated compiled and uncompiled targets within application130. Based on the command, server 456 sends the target subset to loader454. Loader 454, based on the command, may identify a compiled target inthe subset with a same name and/or type that matches the name oforiginal object definition 144A. Loader 454 may load the compiledtarget, for instance, updated object definition 144B, into memory. Uponloading updated object definition 144B into memory, loader 454 maydetermine that original object definition 144A and updated objectdefinition 144B have the same name and/or type. Based on thisdetermination, loader 454 may determine a memory location or address ofupdated object definition 144B and set the $change variable of originalobject definition 144A to the memory location or address of updatedobject definition 144B.

At a later time after updating the $change variable of original objectdefinition 144A to the memory location or address of updated objectdefinition 144B, application 130 may invoke the setFirstName (Stringfirst) method of the USER class. When the setFirstName (String first)method of the USER class is invoked, test environment system 124initially tests the condition if ($changeLocal !=null) to determinewhether $changeLocal includes the memory address of an updated versionof the USER class. Because loader 454 previously set the $changevariable of original object definition 144A to the memory location oraddress of updated object definition 132, the condition resolves totrue. Accordingly, text environment system 124 executes the programlogic $changeLocal.access$dispatch (($changeLocal, “setFirstName (Stringfirst)”, first).

The access$dispatch ( )method includes dispatcher program logic thataccepts the arguments ($changeLocal, “setFirstName (String first)”,first). The dispatcher program logic accesses updated object definition144B based on the reference included in $changeLocal. Upon accessingupdated object definition 144B, the dispatcher executes the method named“setFirstName (String first)”, using the argument first. Updated objectdefinition 144B includes updated program logic provided by the softwaredeveloper to the setFirstName (String first) method, and therefore testenvironment system 124 executes the updated program logic. Because thedispatcher program logic can access the updated compiled target usingthe $changeLocal variable while application 130 is executing, changes infunctionality to the updated compiled target may be tested and observedwithout terminating execution of application module 130. Since theexecution of application module 130 has not been terminated, the objectsstate 134 for existing object instances may remain accessible in memory.As such, changes to the updated compiled target can be tested andobserved using the existing objects state.

As described in FIG. 3, structural changes implemented by a softwaredeveloper to source code in application 130 may not allow application130 to execute updated compiled targets in a test environment system 124without restarting application 130. Structural changes that do notpermit or allow application 130 to execute updated object definition144B without restarting application 130 may include changes to sourcecode that do not support byte-code injection or permit modification ofcompiled targets. In such examples, test environment system 124 mayimplement one or more cold-swapping techniques.

In the example of FIG. 4, server 456 may initially receive anapplication package for application 130 from builder computing system102. Compiler 114 and/or packaging module 358 of FIG. 3 may havemodified one or more compiled or uncompiled targets or inserted codewithin the application package that represents application 130, suchthat application 130 is loaded into memory with newer compiled anduncompiled targets being loaded first in reverse chronological order. Asan example, loader 454 may be a customer classloader that was previouslyincluded in the application package that loads newer compiled anduncompiled targets first in reverse chronological order. In someexamples, if a more recent version of a compiled or uncompiled targethas been loaded into memory, loader 454 may not load the older versioninto memory, thereby ensuring that newer versions of compiled anduncompiled targets are loaded into memory.

When application 130 is loaded by loader 454 in test environment system124, loader 454 may search for and load newer compiled and uncompiledtargets before older compiled and uncompiled targets. Compiled targetswith machine executable code may be stored in a predefined location ordirectory in a filesystem of test environment system 124. The predefinedlocation or directory may be a relative or absolute directory. Asdescribed in FIG. 3, compiler 114 and/or packaging module 358 mayinclude data within the application package for application 130 thatidentifies the predefined location or directory.

At a later time, a software developer may update source code forapplication 130 in such a way that does not allow application 130 toexecute updated compiled targets in test environment system 124 withoutrestarting application 130. Builder module 108 of FIG. 3 may compile theupdated source code into one or more updated compiled targets of ahot-swap target subset as described above in FIG. 3, which includeidentifiers such as $override to indicate that the compiled targets havechanged. Builder module 108 of FIG. 3 may also compile the updatedsource code into one or more updated compiled targets of a cold-swaptarget subset, which include compiled and uncompiled targets, based onthe source code changes, that compiled according to the initial, ratherthan subsequent, compilation process as described above in FIG. 3.

Server 456 may receive the hot-swap target subset and/or the cold-swaptarget subset from builder module 108, while application 130 isexecuting. Coordinator module 459 may receive the hot-swap target subsetand/or the cold-swap target subset from server 456 and store thehot-swap target subset and/or the cold-swap target subset targets in thepredefined location or directory initially specified in applicationpackage representing application 130. In some examples, data identifyingthe predefined location or directory may be hardcoded in coordinator 459or determined by coordinator 459, or dynamically loaded from aconfiguration file into a variable of coordinator 459.

In some examples, server 456 may receive a command from buildercomputing system 102 with the hot-swap target subset and/or thecold-swap target subset targets. Test environment system 124 may, basedon the command (e.g., specifying a cold-swap operation), terminate oneor more processes of application 130 and re-execute application 130.Upon initiating re-execution of application 130, loader 454 may identifycold-swap target subset of compiled targets included in the predefinedlocation or directory initially specified in application packagerepresenting application 130. Loader 454 may determine that an olderversion and newer version (e.g., from the cold-swap target subset) of acompiled target exist in the predefined location or directory. Loader454 may identify the newer version of the compiled target based on adate, timestamp, version number or other identifier that indicates thenewer compiled target is more recent than the older compiled target.Based on this determination, the loader may load the newer compiledtarget first into memory. In this way, application 130 may execute usingthe newer compiled target that was loaded into memory.

As described above, cold-swapping may reduce the amount of time neededto perform a subsequent build and deploy iteration because the targetsubset of updated compiled targets, rather than an entire applicationpackage, is deployed at test environment system 364 in a subsequentiteration. Since application 130, loader 454 and/or coordinator 459includes data to identify the predefined location or directory forcompiled targets that include machine-executable code and load suchcompiled targets in reverse chronological order, application 130 may berestarted with the newest compiled targets being loaded into memory forexecution.

As described in FIG. 3, builder module 108 may implement techniques tosend a target subset of compiled and/or uncompiled targets that havechanged to test environment system 124 and restart one or more threadsof application 130 (without restarting application 130 completely, i.e.,terminating all processes and subsequently initializing execution) inorder to execute the changed compiled and/or uncompiled targets. Suchtechniques may be referred to as “warm-swapping.” As an example ofwarm-swapping, builder module 108 of FIG. 3 may initially build anapplication package that includes target set 112 which may includecompiled and uncompiled targets. For instance, target set 112 mayinclude an uncompiled resource, such as an image that is used byapplication 130. Server 456 may receive the application package frombuilder computing system 108 when the application package is initiallydeployed in test environment 142.

Loader 454 may load one or more compiled resources into memory, andresource manager 460 may load uncompiled targets and/or resources,including the image, into memory. As described in FIG. 3, resourcemanager 460 may be a module that provides one or more applicationprogramming interfaces to applications executing at test environmentsystem 124 so that applications may use resources. Applications mayinvoke the APIs directly or indirectly through libraries 458 to loaduncompiled targets, such as an image for display.

At a later time, a software developer may modify the image or replacethe image with a different image of the same file name. The softwaredeveloper may provide a user input that causes builder module 108 ofFIG. 3 to build and deploy application 130. For instance, as describedin FIG. 3, change detection module 110 may determine that the originalimage has been modified and include the updated image as part of atarget subset, which builder module 108 sends to test environment system124. Server 456 may receive the target subset.

Coordinator 459 may receive the target subset from server 456 and storethe resources in a predefined location or directory in a filesystem oftest environment system 124. The predefined location or directory 452Bmay be a relative or absolute directory. The predefined location ordirectory 452B for resources may be different than or the same as thepredefined location or directory for compiled targets comprised ofmachine-readable code. Resource manager 460 may load uncompiled targetssuch as resources from the predefined location or directory. Resourcemanager 460 may load the resources based on data specifying the locationor directory 460 that is included in the resource manager or theapplication package.

Resource manager 460 may execute as a process or thread. As described inFIG. 3, resource manager 460 may be a process that is forked from or athread that is created by another processor or thread of application130. In other examples, resource manager 460 may be a system process orthread is initiated outside the execution of application 130, but whichcommunicates with application 130 using one or more interprocesscommunication techniques.

When server 456 receives the target subset, coordinator module 459stores the resources, such as the updated image, in the target subset ina temporary file or directory. For instance, coordinator module 459 mayreceive the resources from a server and store them in a temporary fileor directory with a name that is different than the predefined locationor directory 452B that stores the resources and is known to resourcemanager 460. Coordinator 459 may also receive a command to restart theresource manager without restarting application 130 entirely. Based onthe command, coordinator 459 may update the name of the temporary fileor directory that stores the updated resources to the name of thepredefined location or directory that stores the resources 452B and isknown to resource manager 460.

As an example, prior the renaming operation, previous directory 452A mayhave the name of the predefined location or directory that is known toresource manager 460. Previous directory 452A may include originalresources 136A, such as the original image for the application.Coordinator 459 may receive the updated image in a target subset andstore the updated image in directory 452B, which includes updatedresources 136B such as the updated image. Directory 452B may have a nameother than name of the predefined location or directory that is known toresource manager 460. Coordinator module 459 may set the name of thetemporary file or directory 452B that stores updated resources 136B tothe name of the predefined location or directory 452A that storesoriginal resources 136A. In this way, resource manager 460, ifrestarted, will load updated resources 136B from current directory 452B,which has the name of the predefined location or directory that is knownto resource manager 460.

Based on the update of the name of current directory 452B, coordinatormodule 459 may issue a signal or other instruction to resource manager460 to restart the process or thread that implements resource manager460. When resource manager 460 restarts, without terminating orrestarting application 130 entirely, resource manager 460 opens thedirectory 452B known to resource manager 460, which now includes theupdated resources 136B. The newly-instantiated resource manager 460 mayreference the updated resources 136B. In some examples, coordinatormodule 459 may use reflection to identify each compiled target (e.g.,original object definition 144A and/or updated object definition 144B)in memory that references resource manager 460. Coordinator module 459updates the reference to the newly-instantiated resource manager 460,which contains references to the updated resources 136B. Coordinatormodule 459 may use reflection to update these references therebyavoiding the termination of application 130 entirely. In this way,application 130 may exhibit or otherwise display the updated resources136B without entirely restarting application 130.

As described in FIG. 3, builder module 108 may insert patch compactionprogram logic into application 130. The path compaction program logic,when executed in application 130, may determine that at least a firstcompiled target, and a second compiled target that is based at least inpart on the first compiled target, are stored at the test environmentsystem, such as in the directory or location that is known toapplication 130. For each compiled target, application 130 may generatea respective index indicates a respective version of the compiledtarget. In this way, a first version of a compiled USER class may have afirst index representing the first version, and a second version of acompiled USER class may have a second index representing the secondversion. Application 130, when executing the patch compaction programlogic, may determine that the first version of the compiled USER classis more recent than a second version of the compiled USER class, whereinthe first version is indicated by the first index and the second versionis indicated by the second index. Application 130 may delete, based atleast in part on first version being more recent than the secondversion, the second, less recent version of the compiled USER class. Insome examples, if there are additional less recent versions of thecompiled USER class, then application 130 may delete such less versionsas well.

As described in FIG. 3, in some instances, hot- or warm-swapping may notbe possible due to structural changes in the source code that areincorporate into updated compiled targets. In such examples, performinghot- or warm-swapping may fail at test environment system 124. Ratherthan allowing application 130 to crash in an unexpected or unhandledway, application coordinator 459 may revert from hot- or warm-swappingto cold swapping. For instance, if test environment 124 receives acommand to perform a hot- or warm-swap operation and application 130throws or otherwise raises an unhandled error or exception, coordinator459 may catch or receive the exception or error and cause updatedcompiled targets to be applied to application 130 using cold-swapping.As described in FIG. 3, in some examples, builder computing system maysend a hot-swap target subset and/or a cold-swap target subset ofcompiled targets to test environment system 124. In this way, ifcoordinator 459 determines that applying the hot-swap target subset hasfailed, coordinator 459 can apply the cold-swap target subset.

FIG. 5 is a flow diagram illustrating example operations of a buildercomputing system configured to perform hot-swapping techniques, inaccordance with techniques of this disclosure. For purposes ofillustration only, the example operations are described below within thecontext of builder computing system 102 of FIGS. 1 and 3.

Builder computing system 102 may receive an initial user input thatcauses builder computing system 102 to compile a set of source code forapplication 130 into a set of compiled targets (500). For instance,software developer may select an icon or input a command that causesbuilder computing system 102 to initially compiles source code forapplication 130 into a set of compiled targets. Upon compiling thesource code, builder computing system 102 may inject bytecode, asdescribed in FIGS. 1-4, into a compiled target (502). The bytecode mayinclude a conditional statement indicates whether an updated version ofthe compiled target is loaded in memory of the test environment.

Builder computing system 102 may package the set of compiled targets,one or more of which include the injected bytecode, in applicationpackage. Builder computing system 102 may perform one or more additionaloperations on the application package, such as signing, compressing,aligning or any other operations. Builder computing system 102 maydeploy the set of compiled targets as an application package that issent by builder computing system 102 to a test environment system (504).In some examples, deploying the set of compiled targets may includesending a command that causes the test environment to install theapplication package.

Builder computing system 102 may receive a subsequent user input to thatmodifies a subset of the source code. Following the modifies made by theuser, the user may provide a user input that causes builder computingsystem 102 to compile at least a subset of the source code into anupdated subset compiled targets (506). Builder computing system 102 mayinject an indicator, such as a string or other bytecode, into an updatedcompiled target (508). The indicator may indicate that the updatedcompiled target is changed in relation to an original compiled targetthat corresponds to the updated compiled target (e.g., based on being ofthe same type as the original compiled target). Builder computing system102 may deploy the updated subset of compiled targets to updateapplication 130 based on the updated subset without terminatingexecution of application 130 (510). For instance, builder computingsystem 102 may send the updated subset to the test environment. In someexamples, builder computing system 102 may send a command that causesthe test environment to update application 130 without restartingapplication 130.

FIG. 6 is a flow diagram illustrating example operations of a testenvironment system configured to perform hot-swapping techniques, inaccordance with techniques of this disclosure. For purposes ofillustration only, the example operations are described below within thecontext of test environment system 124 of FIG. 4.

Test environment system 124 may initially receive a set of compiledtargets from builder computing system 102 (600). For instance, buildercomputing system 102 may compile a set of source code into compiledtarget, assemble other uncompiled targets, and package the compiled anduncompiled targets into an application package. Builder computing system102 may send this application package to test environment system 124.Builder computing system 102 may load an original compiled target of theset of compiled targets into memory of the test environment system(602). In the example of FIG. 6, the original compiled target mayinclude a conditional statement indicates whether an updated version ofthe compiled target is loaded in memory of the test environment.

Test environment system 124 may receive an updated subset of compiledtargets while the original compiled target is stored in memory (604).For instance, a software developer may have modified source code for theoriginal compiled target and builder computing system 102 may haverecompiled the modified source into an updated compiled target. Theupdated compiled target may include an indicator that indicates theupdated compiled target is changed in relation to the original compiledtarget. Test environment system 124 may set a variable in the originalcompiled target to the location of the updated compiled target in thememory of the test environment system (605).

Test environment system 124 may determine that the compiled targetincludes an indicator that indicates the updated compiled target ischanged in relation to the original compiled target (606). For instance,application 130 may invoke a function or method of the original compiledtarget. The conditional statement that indicates whether an updatedversion of the compiled target is loaded in memory of the testenvironment may resolve to true because the conditional statementincludes the variable that is now set to the location of the updatedcompiled target. In response to determining that the updated compiledtarget is changed in relation to the original version of the compiledtarget, the test environment may execute, without terminating executionof application 130, the updated compiled target in response to aninvocation of program logic, such as the method or function, in theoriginal compiled target (608).

FIG. 7 is a flow diagram illustrating example operations of a buildercomputing system configured to perform cold-swapping techniques, inaccordance with techniques of this disclosure. For purposes ofillustration only, the example operations are described below within thecontext of builder computing system 102 of FIGS. 1 and 3.

Builder computing system 102 may receive an initial user input thatcauses builder computing system 102 to compile a set of source code intoa set of compiled targets of an application package that implements anapplication 130 (700). Builder computing system 102, for instance, maycompile the source code into the compiled targets, assemble otheruncompiled targets, and package the compiled and uncompiled targets intoan application package. Builder computing system 102 may deploy theapplication package by sending the application package to a testenvironment, which executes the contents of the application package(702).

A software developer may later edit a subset of the source code. Thesoftware developer may provide a user input that causes buildercomputing system 102 to compile at least the subset of the set of sourcecode into an updated subset of compiled targets (704). Rather thanre-compiling all the source code into compiled targets, assembling allthe other uncompiled targets, and packaging the compiled and uncompiledtargets into an application package, builder computing system may deploythe updated subset of compiled targets to the test environment withoutsending another application package that includes the updated subset ofcompiled targets (706). In this way, additional processing steps forgenerating, sending, and installing another application package may beavoided by only sending the updated subset of compiled targets to thetest environment.

FIG. 8 is a flow diagram illustrating example operations of a testenvironment system configured to perform cold-swapping techniques, inaccordance with techniques of this disclosure. For purposes ofillustration only, the example operations are described below within thecontext of test environment system 124 of FIG. 4.

In FIG. 8, test environment system 124 may receive a set of compiledtargets of application 130 (800). For instance, builder computing system102 may have generated the set of compiled target in response toreceiving a user input. In some examples, builder computing system 102packages the set of compiled targets into an application package thatrepresents application 130. The application package may include compiledand uncompiled targets. Test environment system 124 may load one or moreof the set of compiled targets into memory of the test environmentsystem, such that application 130 is executing (802).

Test environment system 124 may later receive an updated subset of theset of compiled targets while the original compiled target is stored inmemory (804). For instance, a software developer may modify source codeof application 130 and provide a user input that causes buildercomputing system 102 to compile the modified source code into an updatedset of compiled targets. Builder computing system 102 may send theupdated set of compiled targets to test environment system 124.

Test environment system 124, upon receiving the updated set of compiledtargets may store the updated subset of compiled targets in a predefinedfilesystem location of the target environment that is known byapplication 130 (806). For instance, application 130 may include datathat identifies an absolute or relative directory that represents thepredefined filesystem location. Application 130 may determine that itcannot be updated with the updated subset of compiled targets unlessapplication 130 is restarted. Accordingly, test environment system 124may cause application 130 to restart. That is, test environment system124 may restart the application to execute with the updated subset ofcompiled targets, based at least in part on the updated compiled targetsbeing included in the predefined filesystem location of the targetenvironment (810). For instance, test environment system 124, because itaccesses the predefined filesystem location of the target environmentthat is known by application 130, may execute the updated subset ofcompiled targets included in the predefined filesystem location.

FIG. 9 is a flow diagram illustrating example operations of a buildercomputing system configured to perform warm-swapping techniques, inaccordance with techniques of this disclosure. For purposes ofillustration only, the example operations are described below within thecontext of builder computing system 102 of FIGS. 1 and 3.

As shown in FIG. 9, builder computing system 102 may receive an initialuser input that causes builder computing system 102 to assemble a set ofresources into a set of uncompiled targets of an application packagethat implements application 130 (900). For instance, the initial userinput may cause builder computing system 102 to initially generate theapplication package for application 130. The application package mayinclude a target set that comprises the set of resource and may alsoinclude one or more compiled targets that are compiled based on sourcecode.

Builder computing system 102 may deploy the application package toinitiate execution of application 130 (902). For instance, targetenvironment system 124 may receive the application package from buildercomputing system 102. Target environment system 124 may store theresources of the application package in a predefined filesystem locationof the target environment that is known by application 130. At a latertime, after modification to at least a subset of resources, buildercomputing system 102 may receive a subsequent user input that causesbuilder computing system 102 to assemble an updated subset of the set ofresources that are based on the subset of resources (904). Buildercomputing system 102 may deploy the updated subset of the set ofresources to update the application based on the updated subset withoutsending another application package that includes the updated subset ofthe set of resources (940). In this way, builder computing system 102may send the updated resources without re-generating a new applicationpackage with the complete target set for application 130.

In some examples, the updated subset of resources are stored in atemporary filesystem location of the target environment. Deploying theupdated subset causes a coordinator component of target environmentsystem 124 to update a name of the temporary filesystem location to aname of a predefined filesystem location of the target environment thatis known by application 130. Application 130 may restart to execute withthe updated subset of resources, based at least in part on the updatedsubset of resources being included in the predefined filesystem locationof the target environment.

FIG. 10 is a flow diagram illustrating example operations of a testenvironment system configured to perform warm-swapping techniques, inaccordance with techniques of this disclosure. For purposes ofillustration only, the example operations are described below within thecontext of test environment system 124 of FIG. 4.

Test environment system 124 may initially receive a set of resources ofapplication 130 (1000). For instance, builder computing system 102 mayinitially generate an application package for application 130 that iscomprised of a target set where the target set include the set ofresources and one or more compiled targets that are based on sourcecode. Test environment system 124 may load a resource of the one or moreof the resources into memory of test environment system 124 (1002). Forinstance test environment system 124 may load an image into memory, suchthat application 130 may display the image in a graphical userinterface.

At a later time, a software developer may modify the image or substitutethe contents of one image for another while retaining the same filename. The software developer may provide a user input that causesbuilder computing system 102 to assemble an updated subset of resourcesthat includes the updated image. Upon assembling the updated subset ofresources, builder computing system 102 may send the updated subset ofresources to test environment system 124. Test environment system 124may receive the subset of resources (1004). In response to receiving thesubset of resources, test environment system 124 may store the subset ofresources in a temporary filesystem location of the target environmentsystem 124 (1006).

Test environment system 124 may determine that application 130 cannot beupdated with the updated subset of resources without restarting aresource manager that provides application 130 with access to theresources (1008). Accordingly, test environment system 124 may updatethe temporary filesystem location to a predefined filesystem location ofthe target environment that is known by application 130 (1010). Forinstance, a predefined filesystem location that is known by anapplication may be hardcoded within the application or one or morecomponents of a system runtime, or may be loaded from a configurationfile into the application or one or more components of a system runtime.Upon updating the temporary filesystem location to a predefinedfilesystem location of the target environment that is known by theapplication, test environment system 124 may restart, withoutterminating application 130, the resource manager to load the updatedsubset of resources based at least in part on the updated subset ofresources being included in the predefined filesystem location of thetarget environment system 124 (1012).

Example 1

A method comprising: in response to receiving an initial user input thatcauses a builder computing system to compile a set of source code for anapplication into a set of compiled targets, deploying, by the buildercomputing system, the set of compiled targets to initiate execution ofthe application, wherein a subset of the set of source code is compiledinto an initial subset of the set of compiled targets; aftermodification to at least the subset of the set of source code,receiving, at the builder computing system, a subsequent user input thatcauses the builder computing system to compile at least the subset ofthe set of source code into an updated subset of the set of compiledtargets; and in response to determining that the updated subset differsfrom the initial subset, deploying the updated subset of compiledtargets to update the application without terminating execution of theapplication.

Example 2

The method of Example 1, further comprising: refraining from deployingother compiled targets in the set of compiled targets to update theapplication, wherein the other compiled targets are not included in theupdated subset of the set of compiled targets.

Example 3

The method of any of Examples 1-2, wherein the application is executingat a test environment, wherein the test environment is at least one ofan emulator executing at the builder computing system, a directory ofthe builder computing system, or a remote computing device that isoperably coupled to the builder computing system.

Example 4

The method of any of Examples 1-3, wherein the update of the applicationupdates a compiled target of the initial subset with a reference to acompiled target of the updated subset, wherein the compiled target ofthe initial subset is stored in memory of the test environment duringexecution of the application and prior to deployment of the updated set.

Example 5

The method of any of Examples 1-4, further comprising: injecting, by thebuilder computing system and into at least one compiled target of thetarget set, bytecode that represents a conditional statement, whereinthe bytecode is injected within the compiled target prior to bytecodethat represents program logic of a function in the application, whereinthe conditional statement indicates whether an updated version of thefunction is loaded in memory of the test environment; and injecting, bythe builder computing system and into the at least one compiled target,bytecode that invokes the updated version of the function responsive tothe conditional statement being satisfied.

Example 6

The method of any of Examples 1-5, further comprising: in response tocompiling at least the subset of the set of source code into the updatedsubset of the set of compiled targets, updating, by the buildercomputing device, a name of a compiled target of the updated subset, aname of a variable within the compiled target of the updated subset, ora name of a method within the compiled target of the updated subset,wherein the updated name indicates that the compiled target of theupdated subset is changed in relation to a previous version of thecompiled target.

Example 7

The method of any of Examples 1-6, wherein deploying, by the buildercomputing system, the set of compiled targets to initiate execution ofthe application further comprises packaging the set of compiled targetsinto a first application package that represents the application andsending the application package to a test environment, and whereindeploying the updated subset of compiled targets to update theapplication based on the updated subset further comprises sending theupdated subset of compiled targets to the test environment withoutpackaging the updated subset of compiled targets into a secondapplication package that represents the application.

Example 8

The method of any of Examples 1-7, further comprising: in response todetermining that a class in the subset of the set of source codeincludes at least two super constructors: injecting, by the buildercomputing device, a first set of bytecode that represents program logicthat invokes a new constructor of the inserted by the builder computingdevice; and injecting, by the computing device, a second set of bytecodethat represents the new constructor, wherein the new constructor invokesat least one of the two super constructors based at least in part on aparameter received from the first set of bytecode.

Example 9

A computing device comprising: one or more computer processors; and amemory comprising instructions that when executed by the one or morecomputer processors cause the one or more computer processors to performany of the method of Examples 1-8.

Example 10

A non-transitory computer-readable storage medium encoded withinstructions that, when executed, cause at least one processor of acomputing device to perform any of the method of Examples 1-8.

Example 11

A apparatus comprising means for performing any of the method ofExamples 1-8.

Example 12

A method comprising: in response to receiving a set of compiled targets,loading, by a test environment system, an original compiled target ofthe set of compiled targets into memory of the test environment system,wherein the original compiled target includes a conditional statementthat indicates whether an changed version of the original compiledtarget is stored in memory of the test environment system; in responseto receiving an updated subset of the set of compiled targets while theoriginal compiled target is stored in memory, determining, by the testenvironment system, whether an updated compiled target includes anindicator that indicates the updated compiled target is changed inrelation to the original compiled target; and in response to determiningthat the updated compiled target is changed in relation to the originalversion of the compiled target, executing, by the test environment andwithout terminating execution of the application, the updated compiledtarget in response to an invocation of program logic in the originalcompiled target.

Example 13

The method of Example 12, wherein a type of the original compiled targetis the same as a type of the updated compiled target.

Example 14

The method of any of Examples 12-13, further comprising: in response todetermining that the updated compiled target is changed in relation tothe original version of the compiled target, determining, by the testenvironment system, a location of the updated compiled target in thememory of the test environment system; setting, by the test environmentsystem, a variable in the original compiled target to the location ofthe updated compiled target in the memory of the test environmentsystem; and wherein executing the updated compiled target in response tothe invocation of program logic in the original compiled targetcomprises executing the updated compiled target based at least in parton the variable in the original compiled target.

Example 15

The method of any of Examples 12-14, wherein executing the updatedcompiled target in response to the invocation of program logic in theoriginal compiled target further comprises: in response to theinvocation of program logic in the original compiled target,determining, by the test environment, that the variable in the originalcompiled target includes the location of the updated compiled target inthe memory of the test environment system; and in response todetermining that the variable in the original compiled target includesthe location of the updated compiled target in the memory of the testenvironment system, invoking program logic in the updated compiledtarget that corresponds, based at least in part on a name of the programlogic of the updated compiled target, to program logic in the originalcompiled target.

Example 16

The method of any of Examples 12-15, wherein the indicator thatindicates the updated compiled target is changed in relation to theoriginal compiled target comprises a string that is prepended, inserted,or appended to at least one of a name of a compiled target of theupdated subset, a name of a variable within the compiled target of theupdated subset, or a name of a method within the compiled target of theupdated subset.

Example 17

The method of any of Examples 12-16, wherein executing the compiledtarget further comprises: executing, by the builder computing device, afirst set of bytecode that represents program logic that invokes a newconstructor of the inserted by the builder computing device; andexecuting, by the computing device, a second set of bytecode thatrepresents the new constructor, wherein the new constructor invokes atleast one of two super constructors based at least in part on aparameter received from the first set of bytecode.

Example 18

A computing device comprising: one or more computer processors; and amemory comprising instructions that when executed by the one or morecomputer processors cause the one or more computer processors to performany of the method of Examples 12-17.

Example 19

A non-transitory computer-readable storage medium encoded withinstructions that, when executed, cause at least one processor of acomputing device to perform any of the method of Examples 12-17.

Example 20

An apparatus comprising means for performing any of the method ofExamples 12-17.

Example 21

A method comprising: in response to receiving an initial user input thatcauses a builder computing system to compile a set of source code into aset of compiled targets of an application package that implements anapplication, deploying, by the builder computing system, the applicationpackage to initiate execution of the application, wherein a subset ofthe set of source code is compiled into an initial subset of the set ofcompiled targets; after modification to at least the subset of the setof source code, receiving, at the builder computing system, a subsequentuser input that causes the builder computing system to compile at leastthe subset of the set of source code into an updated subset of the setof compiled targets; and deploying the updated subset of compiledtargets to update the application based on the updated subset withoutsending another application package that includes the updated subset ofcompiled targets.

Example 22

The method of Example 21, wherein the application is executing at a testenvironment and the updated subset of compiled targets are stored in apredefined filesystem location of the target environment that is knownby the application, and wherein deploying the updated subset causes acoordinator component of the target environment to restart theapplication to execute with the updated subset of compiled targets,based at least in part on the updated compiled targets being included inthe predefined filesystem location of the target environment.

Example 23

The method of any of Examples 21-22, wherein the test environment is atleast one of an emulator executing at the builder computing system, adirectory of the builder computing system, or a remote computing devicethat is operably coupled to the builder computing system.

Example 24

The method of any of Examples 21-23, wherein the application comprisesprogram logic to load compiled targets included in the predefined filesystem location in reverse chronological order.

Example 25

The method of any of Examples 21-24, further comprising: sending, by thebuilder computing system, a command that causes the application torestart.

Example 26

The method of any of Examples 21-25, further comprising: whereindeploying the updated subset of compiled targets to update theapplication based on the updated subset without sending anotherapplication package comprises deploying the updated subset of compiledtargets to update the application based on the updated subset withoutsending another application package base at least in part on determiningthat the application cannot be updated with the updated subset ofcompiled targets without restarting the application.

Example 27

The method of any of Examples 21-26, further comprising: inserting, bythe builder computing system, path compaction program logic in theapplication package that when executed in a test environment systemstores respective indices for at least two respective compiled targetsand deletes a first compiled target of the at least two respectivetargets that is less recent than a more recent, second compiled targetof the at least two respective compiled targets.

Example 28

A computing device comprising: one or more computer processors; and amemory comprising instructions that when executed by the one or morecomputer processors cause the one or more computer processors to performany of the method of Examples 21-27.

Example 29

A non-transitory computer-readable storage medium encoded withinstructions that, when executed, cause at least one processor of acomputing device to perform any of the method of Examples 21-27.

Example 30

An apparatus comprising means for performing any of the method ofExamples 20-27.

Example 31

A method comprising: in response to receiving a set of compiled targetsof an application, loading, by a test environment system, one or more ofthe set of compiled targets into memory of the test environment system;in response to receiving an updated subset of the set of compiledtargets while the original compiled target is stored in memory, storing,by the test environment system, the updated subset of compiled targetsin a predefined filesystem location of the target environment that isknown by the application; and in response to determining that theapplication cannot be updated with the updated subset of compiledtargets without restarting the application, restarting, by the testenvironment system, the application to execute with the updated subsetof compiled targets, based at least in part on the updated compiledtargets being included in the predefined filesystem location of thetarget environment.

Example 32

The method of Example 31, wherein the predefined filesystem location ofthe target environment is known by the application, based at least inpart on the predefined filesystem location of the target environmentbeing included as a string within at least a configuration file for theapplication or a compiled target of the set of compiled targets.

Example 33

The method of any of Examples 31-32, further comprising: loading, by theapplication, updated compiled targets included in the predefinedfilesystem location of the target environment in reverse chronologicalorder after restarting the application, wherein a first compiled targetof the updated compiled targets that is more recently compiled than asecond compiled target of the updated compiled targets is loaded intothe memory of the test environment system without loading the secondcompiled target into the memory of the test environment system, whereina type of the first compiled target is the same as a type of the secondcompiled target.

Example 34

The method of any of Examples 31-33, further comprising receiving, bythe test environment system, a command that causes the application torestart.

Example 35

The method of any of Examples 31-34, wherein receiving the set ofcompiled targets of the application comprises receiving a firstapplication package that represents the application and comprises theset of compiled targets of the application, and wherein receiving theupdated subset of compiled targets comprises receiving the updatedsubset of compiled targets that are not included in a second applicationpackage that represents the application.

Example 36

The method of any of Examples 31-35, further comprising: determining, bythe test environment system, that at least a first compiled target and asecond compiled target that is based at least in part on the firstcompiled target are stored at the test environment system; andgenerating respective indices for the first compiled target and thesecond compiled target, wherein each respective index of the firstcompiled target and the second compiled target indicates a respectiveversion of the first compiled target and the second compiled target.

Example 37

The method of any of Examples 21-36, further comprising: determining, bythe test environment system, that a first version of the first compiledtarget is more recent than a second version of the second compiledtarget, wherein the first version is indicated by a first index of thefirst compiled target and the second version is indicated by a secondindex of the second compiled target; and deleting, by the testenvironment system and based at least in part on first version beingmore recent than the second version, the second compiled target.

Example 38

A computing device comprising: one or more computer processors; and amemory comprising instructions that when executed by the one or morecomputer processors cause the one or more computer processors to performany of the method of Examples 31-37.

Example 39

A non-transitory computer-readable storage medium encoded withinstructions that, when executed, cause at least one processor of acomputing device to perform any of the method of Examples 31-37.

Example 40

An apparatus comprising means for performing any of the method ofExamples 31-37.

Example 41

A method comprising: in response to receiving an initial user input thatcauses a builder computing system to assemble a set of resources into aset of uncompiled targets of an application package that implements anapplication, deploying, by the builder computing system, the applicationpackage to initiate execution of the application, wherein the set ofuncompiled targets includes a subset of the set of resources; aftermodification to at least the subset of the set of resources, receiving,at the builder computing system, a subsequent user input that causes thebuilder computing system to assemble an updated subset of the set ofresources that are based on the subset of the set of resources; anddeploying the updated subset of the set of resources to update theapplication based on the updated subset without sending anotherapplication package that includes the updated subset of the set ofresources.

Example 42

The method of Example 41, wherein the application is executing at a testenvironment system and the updated subset of resources are stored in atemporary filesystem location of the target environment, whereindeploying the updated subset causes a coordinator component of thetarget environment to update a name of the temporary filesystem locationto a name of a predefined filesystem location of the target environmentthat is known by the application, and wherein deploying the updatedsubset causes the coordinator component of the target environment torestart the application to execute with the updated subset of resources,based at least in part on the updated subset of resources being includedin the predefined filesystem location of the target environment.

Example 43

The method of any of Examples 41-42, wherein the predefined filesystemlocation of the target environment is known by the application, based atleast in part on the predefined filesystem location of the targetenvironment being included as a string within at least a configurationfile for the application or a compiled target included in theapplication package.

Example 44

The method of any of Examples 41-43, wherein the test environment is atleast one of an emulator executing at the builder computing system, adirectory of the builder computing system, or a remote computing devicethat is operably coupled to the builder computing system.

Example 45

The method of any of Examples 41-44, further comprising: sending, by thebuilder computing system, a command that causes the application torestart and the coordinator component of the target environment toupdate the name of the temporary filesystem location to the name of thepredefined filesystem location of the target environment that is knownby the application.

Example 46

The method of any of Examples 41-45, further comprising: sending, by thebuilder computing system and with set of uncompiled targets, a set ofupdated compiled targets, wherein the updated compiled targets aregenerated based on modifications to source code, wherein originalcompiled targets were generated prior to the updated compiled targetsbased on the source without the modifications.

Example 47

The method of any of Examples 41-46, further comprising: in response todetermining that the application package was previously deployed to thetest environment system, refraining, by the builder computing system,from generating the other application package with the updated subset ofthe set of resources.

Example 48

A computing device comprising: one or more computer processors; and amemory comprising instructions that when executed by the one or morecomputer processors cause the one or more computer processors to performany of the method of Examples 41-47.

Example 49

A non-transitory computer-readable storage medium encoded withinstructions that, when executed, cause at least one processor of acomputing device to perform any of the method of Examples 41-47.

Example 50

An apparatus comprising means for performing any of the method ofExamples 41-47.

Example 51

A method comprising: in response to receiving a set of resources of anapplication, loading, by a test environment system, a resource of theone or more of the resources into memory of the test environment system;in response to receiving an updated subset of the resources while theresource is stored in memory, storing, by the test environment system,the updated subset of resources in a temporary filesystem location ofthe target environment; in response to determining that the applicationcannot be updated with the updated subset of resources withoutrestarting a resource manager that provides the application with accessto the resources, updating, by the test environment system, thetemporary filesystem location to a predefined filesystem location of thetarget environment that is known by the application; and restarting, bythe test environment system and without terminating the application, theresource manager to load the updated subset of resources based at leastin part on the updated subset of resources being included in thepredefined filesystem location of the target environment.

Example 52

The method of Example 51, wherein the application is executing at a testenvironment and the updated subset of compiled targets are stored in atemporary filesystem location of the target environment, whereindeploying the updated subset causes a coordinator component of thetarget environment to update a name of the temporary filesystem locationto a name of a predefined filesystem location of the target environmentthat is known by the application, and wherein deploying the updatedsubset causes the coordinator component of the target environment torestart the application to execute with the updated subset of compiledtargets, based at least in part on the updated compiled targets beingincluded in the predefined filesystem location of the targetenvironment.

Example 53

The method of any of Examples 51-52, wherein the resource manager priorto receiving the updated subset of the resources is a first instance ofthe resource manager, the method further comprising: after receiving theupdated subset of the resources, instantiating a second instance of theresource manager as the resource manager; identifying, by the testenvironment system and using reflection, at least one compiled targetloaded in memory that includes a reference to the first instance of theresource manager; and updating, by the test environment and usingreflection, the at least one compiled target to include a reference tothe second instance of the resource manager.

Example 54

The method of any of Examples 51-53, further comprising: outputting, bythe test environment system and for display, at least one of the updatedsubset of resources without restarting the application.

Example 55

The method of any of Examples 51-54, wherein updating the temporaryfilesystem location to the predefined filesystem location of the targetenvironment that is known by the application comprises renaming thetemporary filesystem location to the predefined filesystem location.

Example 56

The method of any of Examples 51-55, further comprising: receiving, bythe test environment system, a command that causes the application torestart and the coordinator component of the target environment toupdate the name of the temporary filesystem location to the name of thepredefined filesystem location of the target environment that is knownby the application.

Example 57

The method of any of Examples 51-56, further comprising: receiving, bytest environment system and with the set of uncompiled targets, a set ofupdated compiled targets, wherein the updated compiled targets aregenerated based on modifications to source code, wherein originalcompiled targets were generated prior to the updated compiled targetsbased on the source without the modifications.

Example 58

A computing device comprising: one or more computer processors; and amemory comprising instructions that when executed by the one or morecomputer processors cause the one or more computer processors to performany of the method of Examples 51-57.

Example 59

A non-transitory computer-readable storage medium encoded withinstructions that, when executed, cause at least one processor of acomputing device to perform any of the method of Examples 51-57.

Example 60

An apparatus comprising means for performing any of the method ofExamples 51-57.

In one or more examples, the functions described may be implemented inhardware, software, firmware, or any combination thereof. If implementedin software, the functions may be stored on or transmitted over, as oneor more instructions or code, a computer-readable medium and executed bya hardware-based processing unit. Computer-readable media may includecomputer-readable storage media, which corresponds to a tangible mediumsuch as data storage media, or communication media including any mediumthat facilitates transfer of a computer program from one place toanother, e.g., according to a communication protocol. In this manner,computer-readable media generally may correspond to (1) tangiblecomputer-readable storage media, which is non-transitory or (2) acommunication medium such as a signal or carrier wave. Data storagemedia may be any available media that can be accessed by one or morecomputers or one or more processors to retrieve instructions, codeand/or data structures for implementation of the techniques described inthis disclosure. A computer program product may include acomputer-readable medium.

By way of example, and not limitation, such computer-readable storagemedia can comprise RAM, ROM, EEPROM, CD-ROM or other optical diskstorage, magnetic disk storage, or other magnetic storage devices, flashmemory, or any other medium that can be used to store desired programcode in the form of instructions or data structures and that can beaccessed by a computer. Also, any connection is properly termed acomputer-readable medium. For example, if instructions are transmittedfrom a website, server, or other remote source using a coaxial cable,fiber optic cable, twisted pair, digital subscriber line (DSL), orwireless technologies such as infrared, radio, and microwave, then thecoaxial cable, fiber optic cable, twisted pair, DSL, or wirelesstechnologies such as infrared, radio, and microwave are included in thedefinition of medium. It should be understood, however, thatcomputer-readable storage media and data storage media do not includeconnections, carrier waves, signals, or other transient media, but areinstead directed to non-transient, tangible storage media. Disk anddisc, as used, includes compact disc (CD), laser disc, optical disc,digital versatile disc (DVD), floppy disk and Blu-ray disc, where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers. Combinations of the above should also be includedwithin the scope of computer-readable media.

Instructions may be executed by one or more processors, such as one ormore digital signal processors (DSPs), general purpose microprocessors,application specific integrated circuits (ASICs), field programmablelogic arrays (FPGAs), or other equivalent integrated or discrete logiccircuitry. Accordingly, the term “processor,” as used may refer to anyof the foregoing structure or any other structure suitable forimplementation of the techniques described. In addition, in someaspects, the functionality described may be provided within dedicatedhardware and/or software modules. Also, the techniques could be fullyimplemented in one or more circuits or logic elements.

The techniques of this disclosure may be implemented in a wide varietyof devices or apparatuses, including a wireless handset, an integratedcircuit (IC) or a set of ICs (e.g., a chip set). Various components,modules, or units are described in this disclosure to emphasizefunctional aspects of devices configured to perform the disclosedtechniques, but do not necessarily require realization by differenthardware units. Rather, as described above, various units may becombined in a hardware unit or provided by a collection ofinteroperative hardware units, including one or more processors asdescribed above, in conjunction with suitable software and/or firmware.

It is to be recognized that depending on the embodiment, certain acts orevents of any of the methods described herein can be performed in adifferent sequence, may be added, merged, or left out all together(e.g., not all described acts or events are necessary for the practiceof the method). Moreover, in certain embodiments, acts or events may beperformed concurrently, e.g., through multi-threaded processing,interrupt processing, or multiple processors, rather than sequentially.

In some examples, a computer-readable storage medium includes anon-transitory medium. In some examples, the term “non-transitory”indicates that the storage medium is not embodied in a carrier wave or apropagated signal. In certain examples, a non-transitory storage mediummay store data that can, over time, change (e.g., in RAM or cache).

Various examples have been described. These and other examples arewithin the scope of the following claims.

What is claimed is:
 1. A method comprising: in response to receiving aninitial user input that causes a builder computing system to compile aset of source code for an application into a set of compiled targets,deploying, by the builder computing system, the set of compiled targetsto initiate execution of the application, wherein a subset of the set ofsource code is compiled into an initial subset of the set of compiledtargets; after modification to at least the subset of the set of sourcecode, receiving, at the builder computing system, a subsequent userinput that causes the builder computing system to compile at least thesubset of the set of source code into an updated subset of the set ofcompiled targets; and in response to determining that the updated subsetdiffers from the initial subset, deploying the updated subset of the setof compiled targets to update the application without terminatingexecution of the application.
 2. The method of claim 1, furthercomprising: refraining from deploying other compiled targets in the setof compiled targets to update the application, wherein the othercompiled targets are not included in the updated subset of the set ofcompiled targets.
 3. The method of claim 1, wherein the application isexecuting at a test environment, wherein the test environment is atleast one of an emulator executing at the builder computing system, adirectory of the builder computing system, or a remote computing devicethat is operably coupled to the builder computing system.
 4. The methodof claim 3, wherein the update of the application updates a compiledtarget of the initial subset of the set of compiled targets with areference to a compiled target of the updated subset of the set ofcompiled targets, wherein the compiled target of the initial subset ofthe set of compiled targets is stored in memory of the test environmentduring execution of the application and prior to deployment of theupdated subset of the set of compiled targets.
 5. The method of 3,further comprising: injecting, by the builder computing system and intoat least one compiled target of the set of compiled targets, bytecodethat represents a conditional statement, wherein the bytecode isinjected within the at least one compiled target of the set of compiledtargets prior to bytecode that represents program logic of a function inthe application, wherein the conditional statement indicates whether anupdated version of the function is loaded in memory of the testenvironment; and in response to the conditional statement beingsatisfied, injecting, by the builder computing system and into the atleast one compiled target of the set of compiled targets, bytecode thatinvokes the updated version of the function.
 6. The method of claim 1,further comprising: in response to compiling at least the subset of theset of source code into the updated subset of the set of compiledtargets, updating, by the builder computing device, a name of a compiledtarget of the updated subset of the set of compiled targets, a name of avariable within the compiled target of the updated subset of the set ofcompiled targets, or a name of a function within the compiled target ofthe updated subset of the set of compiled targets, wherein the updatedname indicates that the compiled target of the updated subset of the setof compiled targets is changed in relation to a previous version of thecompiled target.
 7. The method of claim 1, wherein deploying, by thebuilder computing system, the set of compiled targets to initiateexecution of the application further comprises packaging the set ofcompiled targets of the set of compiled targets into a first applicationpackage that represents the application and sending the applicationpackage to a test environment, and wherein deploying the updated subsetof the set of compiled targets to update the application based on theupdated subset of the set of compiled targets further comprises sendingthe updated subset of the set of compiled targets to the testenvironment without packaging the updated subset of the set of compiledtargets into a second application package that represents theapplication.
 8. The method of claim 1, further comprising: in responseto determining that a class in the subset of the set of source codeincludes at least two super constructors: injecting, by the buildercomputing device, a first set of bytecode that represents program logicthat invokes a new constructor; and injecting, by the computing device,a second set of bytecode that represents the new constructor, whereinthe new constructor invokes at least one of the two super constructorsbased at least in part on a parameter received from the first set ofbytecode.
 9. A computing device comprising: one or more computerprocessors; and a memory comprising instructions that, when executed bythe one or more computer processors, cause the one or more computerprocessors to: in response to receiving an initial user input thatcauses the computing device to compile a set of source code for anapplication into a set of compiled targets, deploy the set of compiledtargets to initiate execution of the application, wherein a subset ofthe set of source code is compiled into an initial subset of the set ofcompiled targets; after modification to at least the subset of the setof source code, receive a subsequent user input that causes thecomputing device to compile at least the subset of the set of sourcecode into an updated subset of the set of compiled targets; and inresponse to determining that the updated subset of the set of compiledtargets differs from the initial subset of the set of compiled targets,deploy the updated subset of the set of compiled targets to update theapplication without terminating execution of the application.
 10. Anon-transitory computer-readable storage medium encoded withinstructions that, when executed, cause at least one processor of acomputing device to: in response to receiving an initial user input thatcauses the computing device to compile a set of source code for anapplication into a set of compiled targets, deploy the set of compiledtargets to initiate execution of the application, wherein a subset ofthe set of source code is compiled into an initial subset of the set ofcompiled targets; after modification to at least the subset of the setof source code, receive a subsequent user input that causes thecomputing device to compile at least the subset of the set of sourcecode into an updated subset of the set of the set of compiled targets;and in response to determining that the updated subset of the set ofcompiled targets differs from the initial subset of the set of compiledtargets, deploy the updated subset of the set of compiled targets toupdate the application without terminating execution of the application.11. A method comprising: in response to receiving a set of compiledtargets, loading, by a test environment system, an original compiledtarget of the set of compiled targets into memory of the testenvironment system, wherein the original compiled target includes aconditional statement that indicates whether a changed version of theoriginal compiled target is stored in memory of the test environmentsystem; in response to receiving an updated subset of the set ofcompiled targets while the original compiled target is stored in memory,determining, by the test environment system, whether an updated compiledtarget includes an indicator that indicates the updated compiled targetis changed in relation to the original compiled target; and in responseto determining that the updated compiled target is changed in relationto the original version of the compiled target and in response to aninvocation of program logic in the original compiled target, executing,by the test environment and without terminating execution of theapplication, the updated compiled target.
 12. The method of claim 11,wherein a type of the original compiled target is the same as a type ofthe updated compiled target.
 13. The method of claim 11, furthercomprising: in response to determining that the updated compiled targetis changed in relation to the original version of the compiled target,determining, by the test environment system, a location of the updatedcompiled target in the memory of the test environment system; andsetting, by the test environment system, a variable in the originalcompiled target to the location of the updated compiled target in thememory of the test environment system, wherein executing the updatedcompiled target in response to the invocation of program logic in theoriginal compiled target comprises executing the updated compiled targetbased at least in part on the variable in the original compiled target.14. The method of claim 13, wherein executing the updated compiledtarget in response to the invocation of program logic in the originalcompiled target further comprises: in response to the invocation ofprogram logic in the original compiled target, determining, by the testenvironment, that the variable in the original compiled target includesthe location of the updated compiled target in the memory of the testenvironment system; and in response to determining that the variable inthe original compiled target includes the location of the updatedcompiled target in the memory of the test environment system, invokingprogram logic in the updated compiled target that corresponds, based atleast in part on a name of the program logic of the updated compiledtarget, to program logic in the original compiled target.
 15. The methodof claim 11, wherein the indicator that indicates the updated compiledtarget is changed in relation to the original compiled target comprisesa string that is prepended, inserted, or appended to at least one of aname of a compiled target of the updated subset, a name of a variablewithin the compiled target of the updated subset, or a name of afunction within the compiled target of the updated subset.
 16. Themethod of claim 11, wherein executing the compiled target furthercomprises: executing, by the test environment system, a first set ofbytecode that represents program logic that invokes a new constructor;and executing, by the test environment system, a second set of bytecodethat represents the new constructor, wherein the new constructorinvokes, based at least in part on a parameter received from the firstset of bytecode, at least one of two super constructors.
 17. A testenvironment system comprising: one or more computer processors; and amemory comprising instructions that when executed by the one or morecomputer processors cause the one or more computer processors to: inresponse to receiving a set of compiled targets, load an originalcompiled target of the set of compiled targets into memory of the testenvironment system, wherein the original compiled target includes aconditional statement that indicates whether a changed version of theoriginal compiled target is stored in memory of the test environmentsystem; in response to receiving an updated subset of the set ofcompiled targets while the original compiled target is stored in memory,determine whether an updated compiled target includes an indicator thatindicates the updated compiled target is changed in relation to theoriginal compiled target; and in response to determining that theupdated compiled target is changed in relation to the original versionof the compiled target and in response to an invocation of program logicin the original compiled target, execute, without terminating executionof the application, the updated compiled target.
 18. The testenvironment system of claim 17, wherein a type of the original compiledtarget is the same as a type of the updated compiled target.
 19. Thetest environment system of claim 17, wherein the memory comprisesinstructions that when executed by the one or more computer processorscause the one or more computer processors to: in response to determiningthat the updated compiled target is changed in relation to the originalversion of the compiled target, determine a location of the updatedcompiled target in the memory of the test environment system; and set avariable in the original compiled target to the location of the updatedcompiled target in the memory of the test environment system, whereinexecution of the updated compiled target in response to the invocationof program logic in the original compiled target comprises execution ofthe updated compiled target based at least in part on the variable inthe original compiled target.
 20. A non-transitory computer-readablestorage medium encoded with instructions that, when executed, cause atleast one processor of a test environment system to: in response toreceiving a set of compiled targets, load an original compiled target ofthe set of compiled targets into memory of the test environment system,wherein the original compiled target includes a conditional statementthat indicates whether a changed version of the original compiled targetis stored in memory of the test environment system; in response toreceiving an updated subset of the set of compiled targets while theoriginal compiled target is stored in memory, determine whether anupdated compiled target includes an indicator that indicates the updatedcompiled target is changed in relation to the original compiled target;and in response to determining that the updated compiled target ischanged in relation to the original version of the compiled target,execute, without terminating execution of the application, the updatedcompiled target in response to an invocation of program logic in theoriginal compiled target.